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43959 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
ca7e917769 |
Merge tag 'x86-apic-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 APIC updates from Thomas Gleixner:
"Rework of APIC enumeration and topology evaluation.
The current implementation has a couple of shortcomings:
- It fails to handle hybrid systems correctly.
- The APIC registration code which handles CPU number assignents is
in the middle of the APIC code and detached from the topology
evaluation.
- The various mechanisms which enumerate APICs, ACPI, MPPARSE and
guest specific ones, tweak global variables as they see fit or in
case of XENPV just hack around the generic mechanisms completely.
- The CPUID topology evaluation code is sprinkled all over the vendor
code and reevaluates global variables on every hotplug operation.
- There is no way to analyze topology on the boot CPU before bringing
up the APs. This causes problems for infrastructure like PERF which
needs to size certain aspects upfront or could be simplified if
that would be possible.
- The APIC admission and CPU number association logic is
incomprehensible and overly complex and needs to be kept around
after boot instead of completing this right after the APIC
enumeration.
This update addresses these shortcomings with the following changes:
- Rework the CPUID evaluation code so it is common for all vendors
and provides information about the APIC ID segments in a uniform
way independent of the number of segments (Thread, Core, Module,
..., Die, Package) so that this information can be computed instead
of rewriting global variables of dubious value over and over.
- A few cleanups and simplifcations of the APIC, IO/APIC and related
interfaces to prepare for the topology evaluation changes.
- Seperation of the parser stages so the early evaluation which tries
to find the APIC address can be seperately overridden from the late
evaluation which enumerates and registers the local APIC as further
preparation for sanitizing the topology evaluation.
- A new registration and admission logic which
- encapsulates the inner workings so that parsers and guest logic
cannot longer fiddle in it
- uses the APIC ID segments to build topology bitmaps at
registration time
- provides a sane admission logic
- allows to detect the crash kernel case, where CPU0 does not run
on the real BSP, automatically. This is required to prevent
sending INIT/SIPI sequences to the real BSP which would reset
the whole machine. This was so far handled by a tedious command
line parameter, which does not even work in nested crash
scenarios.
- Associates CPU number after the enumeration completed and
prevents the late registration of APICs, which was somehow
tolerated before.
- Converting all parsers and guest enumeration mechanisms over to the
new interfaces.
This allows to get rid of all global variable tweaking from the
parsers and enumeration mechanisms and sanitizes the XEN[PV]
handling so it can use CPUID evaluation for the first time.
- Mopping up existing sins by taking the information from the APIC ID
segment bitmaps.
This evaluates hybrid systems correctly on the boot CPU and allows
for cleanups and fixes in the related drivers, e.g. PERF.
The series has been extensively tested and the minimal late fallout
due to a broken ACPI/MADT table has been addressed by tightening the
admission logic further"
* tag 'x86-apic-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
x86/topology: Ignore non-present APIC IDs in a present package
x86/apic: Build the x86 topology enumeration functions on UP APIC builds too
smp: Provide 'setup_max_cpus' definition on UP too
smp: Avoid 'setup_max_cpus' namespace collision/shadowing
x86/bugs: Use fixed addressing for VERW operand
x86/cpu/topology: Get rid of cpuinfo::x86_max_cores
x86/cpu/topology: Provide __num_[cores|threads]_per_package
x86/cpu/topology: Rename topology_max_die_per_package()
x86/cpu/topology: Rename smp_num_siblings
x86/cpu/topology: Retrieve cores per package from topology bitmaps
x86/cpu/topology: Use topology logical mapping mechanism
x86/cpu/topology: Provide logical pkg/die mapping
x86/cpu/topology: Simplify cpu_mark_primary_thread()
x86/cpu/topology: Mop up primary thread mask handling
x86/cpu/topology: Use topology bitmaps for sizing
x86/cpu/topology: Let XEN/PV use topology from CPUID/MADT
x86/xen/smp_pv: Count number of vCPUs early
x86/cpu/topology: Assign hotpluggable CPUIDs during init
x86/cpu/topology: Reject unknown APIC IDs on ACPI hotplug
x86/topology: Add a mechanism to track topology via APIC IDs
...
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Linus Torvalds
|
d08c407f71 |
Merge tag 'timers-core-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"A large set of updates and features for timers and timekeeping:
- The hierarchical timer pull model
When timer wheel timers are armed they are placed into the timer
wheel of a CPU which is likely to be busy at the time of expiry.
This is done to avoid wakeups on potentially idle CPUs.
This is wrong in several aspects:
1) The heuristics to select the target CPU are wrong by
definition as the chance to get the prediction right is
close to zero.
2) Due to #1 it is possible that timers are accumulated on
a single target CPU
3) The required computation in the enqueue path is just overhead
for dubious value especially under the consideration that the
vast majority of timer wheel timers are either canceled or
rearmed before they expire.
The timer pull model avoids the above by removing the target
computation on enqueue and queueing timers always on the CPU on
which they get armed.
This is achieved by having separate wheels for CPU pinned timers
and global timers which do not care about where they expire.
As long as a CPU is busy it handles both the pinned and the global
timers which are queued on the CPU local timer wheels.
When a CPU goes idle it evaluates its own timer wheels:
- If the first expiring timer is a pinned timer, then the global
timers can be ignored as the CPU will wake up before they
expire.
- If the first expiring timer is a global timer, then the expiry
time is propagated into the timer pull hierarchy and the CPU
makes sure to wake up for the first pinned timer.
The timer pull hierarchy organizes CPUs in groups of eight at the
lowest level and at the next levels groups of eight groups up to
the point where no further aggregation of groups is required, i.e.
the number of levels is log8(NR_CPUS). The magic number of eight
has been established by experimention, but can be adjusted if
needed.
In each group one busy CPU acts as the migrator. It's only one CPU
to avoid lock contention on remote timer wheels.
The migrator CPU checks in its own timer wheel handling whether
there are other CPUs in the group which have gone idle and have
global timers to expire. If there are global timers to expire, the
migrator locks the remote CPU timer wheel and handles the expiry.
Depending on the group level in the hierarchy this handling can
require to walk the hierarchy downwards to the CPU level.
Special care is taken when the last CPU goes idle. At this point
the CPU is the systemwide migrator at the top of the hierarchy and
it therefore cannot delegate to the hierarchy. It needs to arm its
own timer device to expire either at the first expiring timer in
the hierarchy or at the first CPU local timer, which ever expires
first.
This completely removes the overhead from the enqueue path, which
is e.g. for networking a true hotpath and trades it for a slightly
more complex idle path.
This has been in development for a couple of years and the final
series has been extensively tested by various teams from silicon
vendors and ran through extensive CI.
There have been slight performance improvements observed on network
centric workloads and an Intel team confirmed that this allows them
to power down a die completely on a mult-die socket for the first
time in a mostly idle scenario.
There is only one outstanding ~1.5% regression on a specific
overloaded netperf test which is currently investigated, but the
rest is either positive or neutral performance wise and positive on
the power management side.
- Fixes for the timekeeping interpolation code for cross-timestamps:
cross-timestamps are used for PTP to get snapshots from hardware
timers and interpolated them back to clock MONOTONIC. The changes
address a few corner cases in the interpolation code which got the
math and logic wrong.
- Simplifcation of the clocksource watchdog retry logic to
automatically adjust to handle larger systems correctly instead of
having more incomprehensible command line parameters.
- Treewide consolidation of the VDSO data structures.
- The usual small improvements and cleanups all over the place"
* tag 'timers-core-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (62 commits)
timer/migration: Fix quick check reporting late expiry
tick/sched: Fix build failure for CONFIG_NO_HZ_COMMON=n
vdso/datapage: Quick fix - use asm/page-def.h for ARM64
timers: Assert no next dyntick timer look-up while CPU is offline
tick: Assume timekeeping is correctly handed over upon last offline idle call
tick: Shut down low-res tick from dying CPU
tick: Split nohz and highres features from nohz_mode
tick: Move individual bit features to debuggable mask accesses
tick: Move got_idle_tick away from common flags
tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode
tick: Move broadcast cancellation up to CPUHP_AP_TICK_DYING
tick: Move tick cancellation up to CPUHP_AP_TICK_DYING
tick: Start centralizing tick related CPU hotplug operations
tick/sched: Don't clear ts::next_tick again in can_stop_idle_tick()
tick/sched: Rename tick_nohz_stop_sched_tick() to tick_nohz_full_stop_tick()
tick: Use IS_ENABLED() whenever possible
tick/sched: Remove useless oneshot ifdeffery
tick/nohz: Remove duplicate between lowres and highres handlers
tick/nohz: Remove duplicate between tick_nohz_switch_to_nohz() and tick_setup_sched_timer()
hrtimer: Select housekeeping CPU during migration
...
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Linus Torvalds
|
80a76c60e5 |
Merge tag 'timers-ptp-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull clocksource updates from Thomas Gleixner: "Updates for timekeeping and PTP core. The cross-timestamp mechanism which allows to correlate hardware clocks uses clocksource pointers for describing the correlation. That's suboptimal as drivers need to obtain the pointer, which requires needless exports and exposing internals. This can all be completely avoided by assigning clocksource IDs and using them for describing the correlated clock source. So this adds clocksource IDs to all clocksources in the tree which can be exposed to this mechanism and removes the pointer and now needless exports. A related improvement for the core and the correlation handling has not made it this time, but is expected to get ready for the next round" * tag 'timers-ptp-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kvmclock: Unexport kvmclock clocksource treewide: Remove system_counterval_t.cs, which is never read timekeeping: Evaluate system_counterval_t.cs_id instead of .cs ptp/kvm, arm_arch_timer: Set system_counterval_t.cs_id to constant x86/kvm, ptp/kvm: Add clocksource ID, set system_counterval_t.cs_id x86/tsc: Add clocksource ID, set system_counterval_t.cs_id timekeeping: Add clocksource ID to struct system_counterval_t x86/tsc: Correct kernel-doc notation |
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Linus Torvalds
|
397935e3dd |
Merge tag 'smp-core-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu core updates from Thomas Gleixner: "A small boring set of cleanups for the SMP and CPU hotplug code" * tag 'smp-core-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu: Remove stray semicolon smp: Make __smp_processor_id() 0-argument macro cpu: Mark cpu_possible_mask as __ro_after_init kernel/cpu: Convert snprintf() to sysfs_emit() cpu/hotplug: Delete an extraneous kernel-doc description |
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Linus Torvalds
|
4527e83780 |
Merge tag 'irq-msi-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull MSI updates from Thomas Gleixner:
"Updates for the MSI interrupt subsystem and initial RISC-V MSI
support.
The core changes have been adopted from previous work which converted
ARM[64] to the new per device MSI domain model, which was merged to
support multiple MSI domain per device. The ARM[64] changes are being
worked on too, but have not been ready yet. The core and platform-MSI
changes have been split out to not hold up RISC-V and to avoid that
RISC-V builds on the scheduled for removal interfaces.
The core support provides new interfaces to handle wire to MSI bridges
in a straight forward way and introduces new platform-MSI interfaces
which are built on top of the per device MSI domain model.
Once ARM[64] is converted over the old platform-MSI interfaces and the
related ugliness in the MSI core code will be removed.
The actual MSI parts for RISC-V were finalized late and have been
post-poned for the next merge window.
Drivers:
- Add a new driver for the Andes hart-level interrupt controller
- Rework the SiFive PLIC driver to prepare for MSI suport
- Expand the RISC-V INTC driver to support the new RISC-V AIA
controller which provides the basis for MSI on RISC-V
- A few fixup for the fallout of the core changes"
* tag 'irq-msi-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits)
irqchip/riscv-intc: Fix low-level interrupt handler setup for AIA
x86/apic/msi: Use DOMAIN_BUS_GENERIC_MSI for HPET/IO-APIC domain search
genirq/matrix: Dynamic bitmap allocation
irqchip/riscv-intc: Add support for RISC-V AIA
irqchip/sifive-plic: Improve locking safety by using irqsave/irqrestore
irqchip/sifive-plic: Parse number of interrupts and contexts early in plic_probe()
irqchip/sifive-plic: Cleanup PLIC contexts upon irqdomain creation failure
irqchip/sifive-plic: Use riscv_get_intc_hwnode() to get parent fwnode
irqchip/sifive-plic: Use devm_xyz() for managed allocation
irqchip/sifive-plic: Use dev_xyz() in-place of pr_xyz()
irqchip/sifive-plic: Convert PLIC driver into a platform driver
irqchip/riscv-intc: Introduce Andes hart-level interrupt controller
irqchip/riscv-intc: Allow large non-standard interrupt number
genirq/irqdomain: Don't call ops->select for DOMAIN_BUS_ANY tokens
irqchip/imx-intmux: Handle pure domain searches correctly
genirq/msi: Provide MSI_FLAG_PARENT_PM_DEV
genirq/irqdomain: Reroute device MSI create_mapping
genirq/msi: Provide allocation/free functions for "wired" MSI interrupts
genirq/msi: Optionally use dev->fwnode for device domain
genirq/msi: Provide DOMAIN_BUS_WIRED_TO_MSI
...
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Linus Torvalds
|
02d4df78c5 |
Merge tag 'irq-core-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
"Core:
- Make affinity changes take effect immediately for interrupt
threads. This reduces the impact on isolated CPUs as it pulls over
the thread right away instead of doing it after the next hardware
interrupt arrived.
- Cleanup and improvements for the interrupt chip simulator
- Deduplication of the interrupt descriptor initialization code so
the sparse and non-sparse mode share more code.
Drivers:
- A set of conversions to platform_drivers::remove_new() which gets
rid of the pointless return value.
- A new driver for the Starfive JH8100 SoC
- Support for Amlogic-T7 SoCs
- Improvement for the interrupt handling and EOI management for the
loongson interrupt controller.
- The usual fixes and improvements all over the place"
* tag 'irq-core-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
irqchip/ts4800: Convert to platform_driver::remove_new() callback
irqchip/stm32-exti: Convert to platform_driver::remove_new() callback
irqchip/renesas-rza1: Convert to platform_driver::remove_new() callback
irqchip/renesas-irqc: Convert to platform_driver::remove_new() callback
irqchip/renesas-intc-irqpin: Convert to platform_driver::remove_new() callback
irqchip/pruss-intc: Convert to platform_driver::remove_new() callback
irqchip/mvebu-pic: Convert to platform_driver::remove_new() callback
irqchip/madera: Convert to platform_driver::remove_new() callback
irqchip/ls-scfg-msi: Convert to platform_driver::remove_new() callback
irqchip/keystone: Convert to platform_driver::remove_new() callback
irqchip/imx-irqsteer: Convert to platform_driver::remove_new() callback
irqchip/imx-intmux: Convert to platform_driver::remove_new() callback
irqchip/imgpdc: Convert to platform_driver::remove_new() callback
irqchip: Add StarFive external interrupt controller
dt-bindings: interrupt-controller: Add starfive,jh8100-intc
arm64: dts: Add gpio_intc node for Amlogic-T7 SoCs
irqchip/meson-gpio: Add support for Amlogic-T7 SoCs
dt-bindings: interrupt-controller: Add support for Amlogic-T7 SoCs
irqchip/vic: Fix a kernel-doc warning
genirq: Wake interrupt threads immediately when changing affinity
...
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Linus Torvalds
|
045395d86a |
Merge tag 'cgroup-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "A quiet cycle. One trivial doc update patch. Two patches to drop the now defunct memory_spread_slab feature from cgroup1 cpuset" * tag 'cgroup-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup/cpuset: Mark memory_spread_slab as obsolete cgroup/cpuset: Remove cpuset_do_slab_mem_spread() docs: cgroup-v1: add missing code-block tags |
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Linus Torvalds
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1a1e09890c |
Merge tag 'wq-for-6.9-bh-conversions' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue BH conversions from Tejun Heo: "This contains two patches that convert tasklet users to BH workqueues: backtracetest and usb hcd. DM conversions are being routed through the respective subsystem tree. Hopefully, the next cycle will see a lot more conversions" * tag 'wq-for-6.9-bh-conversions' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: usb: core: hcd: Convert from tasklet to BH workqueue backtracetest: Convert from tasklet to BH workqueue |
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Linus Torvalds
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ff887eb07c |
Merge tag 'wq-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
"This cycle, a lot of workqueue changes including some that are
significant and invasive.
- During v6.6 cycle, unbound workqueues were updated so that they are
more topology aware and flexible, which among other things improved
workqueue behavior on modern multi-L3 CPUs. In the process, commit
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Linus Torvalds
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e5a3878c94 |
Merge tag 'rcu.next.v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux
Pull RCU updates from Boqun Feng:
- Eliminate deadlocks involving do_exit() and RCU tasks, by Paul:
Instead of SRCU read side critical sections, now a percpu list is
used in do_exit() for scaning yet-to-exit tasks
- Fix a deadlock due to the dependency between workqueue and RCU
expedited grace period, reported by Anna-Maria Behnsen and Thomas
Gleixner and fixed by Frederic: Now RCU expedited always uses its own
kthread worker instead of a workqueue
- RCU NOCB updates, code cleanups, unnecessary barrier removals and
minor bug fixes
- Maintain real-time response in rcu_tasks_postscan() and a minor fix
for tasks trace quiescence check
- Misc updates, comments and readibility improvement, boot time
parameter for lazy RCU and rcutorture improvement
- Documentation updates
* tag 'rcu.next.v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux: (34 commits)
rcu-tasks: Maintain real-time response in rcu_tasks_postscan()
rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks
rcu-tasks: Maintain lists to eliminate RCU-tasks/do_exit() deadlocks
rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks
rcu-tasks: Initialize callback lists at rcu_init() time
rcu-tasks: Add data to eliminate RCU-tasks/do_exit() deadlocks
rcu-tasks: Repair RCU Tasks Trace quiescence check
rcu/sync: remove un-used rcu_sync_enter_start function
rcutorture: Suppress rtort_pipe_count warnings until after stalls
srcu: Improve comments about acceleration leak
rcu: Provide a boot time parameter to control lazy RCU
rcu: Rename jiffies_till_flush to jiffies_lazy_flush
doc: Update checklist.rst discussion of callback execution
doc: Clarify use of slab constructors and SLAB_TYPESAFE_BY_RCU
context_tracking: Fix kerneldoc headers for __ct_user_{enter,exit}()
doc: Add EARLY flag to early-parsed kernel boot parameters
doc: Add CONFIG_RCU_STRICT_GRACE_PERIOD to checklist.rst
doc: Make checklist.rst note that spinlocks are implied RCU readers
doc: Make whatisRCU.rst note that spinlocks are RCU readers
doc: Spinlocks are implied RCU readers
...
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Linus Torvalds
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1ddeeb2a05 |
Merge tag 'for-6.9/block-20240310' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- MD pull requests via Song:
- Cleanup redundant checks (Yu Kuai)
- Remove deprecated headers (Marc Zyngier, Song Liu)
- Concurrency fixes (Li Lingfeng)
- Memory leak fix (Li Nan)
- Refactor raid1 read_balance (Yu Kuai, Paul Luse)
- Clean up and fix for md_ioctl (Li Nan)
- Other small fixes (Gui-Dong Han, Heming Zhao)
- MD atomic limits (Christoph)
- NVMe pull request via Keith:
- RDMA target enhancements (Max)
- Fabrics fixes (Max, Guixin, Hannes)
- Atomic queue_limits usage (Christoph)
- Const use for class_register (Ricardo)
- Identification error handling fixes (Shin'ichiro, Keith)
- Improvement and cleanup for cached request handling (Christoph)
- Moving towards atomic queue limits. Core changes and driver bits so
far (Christoph)
- Fix UAF issues in aoeblk (Chun-Yi)
- Zoned fix and cleanups (Damien)
- s390 dasd cleanups and fixes (Jan, Miroslav)
- Block issue timestamp caching (me)
- noio scope guarding for zoned IO (Johannes)
- block/nvme PI improvements (Kanchan)
- Ability to terminate long running discard loop (Keith)
- bdev revalidation fix (Li)
- Get rid of old nr_queues hack for kdump kernels (Ming)
- Support for async deletion of ublk (Ming)
- Improve IRQ bio recycling (Pavel)
- Factor in CPU capacity for remote vs local completion (Qais)
- Add shared_tags configfs entry for null_blk (Shin'ichiro
- Fix for a regression in page refcounts introduced by the folio
unification (Tony)
- Misc fixes and cleanups (Arnd, Colin, John, Kunwu, Li, Navid,
Ricardo, Roman, Tang, Uwe)
* tag 'for-6.9/block-20240310' of git://git.kernel.dk/linux: (221 commits)
block: partitions: only define function mac_fix_string for CONFIG_PPC_PMAC
block/swim: Convert to platform remove callback returning void
cdrom: gdrom: Convert to platform remove callback returning void
block: remove disk_stack_limits
md: remove mddev->queue
md: don't initialize queue limits
md/raid10: use the atomic queue limit update APIs
md/raid5: use the atomic queue limit update APIs
md/raid1: use the atomic queue limit update APIs
md/raid0: use the atomic queue limit update APIs
md: add queue limit helpers
md: add a mddev_is_dm helper
md: add a mddev_add_trace_msg helper
md: add a mddev_trace_remap helper
bcache: move calculation of stripe_size and io_opt into bcache_device_init
virtio_blk: Do not use disk_set_max_open/active_zones()
aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts
block: move capacity validation to blkpg_do_ioctl()
block: prevent division by zero in blk_rq_stat_sum()
drbd: atomically update queue limits in drbd_reconsider_queue_parameters
...
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Linus Torvalds
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910202f00a |
Merge tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull block handle updates from Christian Brauner:
"Last cycle we changed opening of block devices, and opening a block
device would return a bdev_handle. This allowed us to implement
support for restricting and forbidding writes to mounted block
devices. It was accompanied by converting and adding helpers to
operate on bdev_handles instead of plain block devices.
That was already a good step forward but ultimately it isn't necessary
to have special purpose helpers for opening block devices internally
that return a bdev_handle.
Fundamentally, opening a block device internally should just be
equivalent to opening files. So now all internal opens of block
devices return files just as a userspace open would. Instead of
introducing a separate indirection into bdev_open_by_*() via struct
bdev_handle bdev_file_open_by_*() is made to just return a struct
file. Opening and closing a block device just becomes equivalent to
opening and closing a file.
This all works well because internally we already have a pseudo fs for
block devices and so opening block devices is simple. There's a few
places where we needed to be careful such as during boot when the
kernel is supposed to mount the rootfs directly without init doing it.
Here we need to take care to ensure that we flush out any asynchronous
file close. That's what we already do for opening, unpacking, and
closing the initramfs. So nothing new here.
The equivalence of opening and closing block devices to regular files
is a win in and of itself. But it also has various other advantages.
We can remove struct bdev_handle completely. Various low-level helpers
are now private to the block layer. Other helpers were simply
removable completely.
A follow-up series that is already reviewed build on this and makes it
possible to remove bdev->bd_inode and allows various clean ups of the
buffer head code as well. All places where we stashed a bdev_handle
now just stash a file and use simple accessors to get to the actual
block device which was already the case for bdev_handle"
* tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
block: remove bdev_handle completely
block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access
bdev: remove bdev pointer from struct bdev_handle
bdev: make struct bdev_handle private to the block layer
bdev: make bdev_{release, open_by_dev}() private to block layer
bdev: remove bdev_open_by_path()
reiserfs: port block device access to file
ocfs2: port block device access to file
nfs: port block device access to files
jfs: port block device access to file
f2fs: port block device access to files
ext4: port block device access to file
erofs: port device access to file
btrfs: port device access to file
bcachefs: port block device access to file
target: port block device access to file
s390: port block device access to file
nvme: port block device access to file
block2mtd: port device access to files
bcache: port block device access to files
...
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Linus Torvalds
|
b5683a37c8 |
Merge tag 'vfs-6.9.pidfd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull pdfd updates from Christian Brauner:
- Until now pidfds could only be created for thread-group leaders but
not for threads. There was no technical reason for this. We simply
had no users that needed support for this. Now we do have users that
need support for this.
This introduces a new PIDFD_THREAD flag for pidfd_open(). If that
flag is set pidfd_open() creates a pidfd that refers to a specific
thread.
In addition, we now allow clone() and clone3() to be called with
CLONE_PIDFD | CLONE_THREAD which wasn't possible before.
A pidfd that refers to an individual thread differs from a pidfd that
refers to a thread-group leader:
(1) Pidfds are pollable. A task may poll a pidfd and get notified
when the task has exited.
For thread-group leader pidfds the polling task is woken if the
thread-group is empty. In other words, if the thread-group
leader task exits when there are still threads alive in its
thread-group the polling task will not be woken when the
thread-group leader exits but rather when the last thread in the
thread-group exits.
For thread-specific pidfds the polling task is woken if the
thread exits.
(2) Passing a thread-group leader pidfd to pidfd_send_signal() will
generate thread-group directed signals like kill(2) does.
Passing a thread-specific pidfd to pidfd_send_signal() will
generate thread-specific signals like tgkill(2) does.
The default scope of the signal is thus determined by the type
of the pidfd.
Since use-cases exist where the default scope of the provided
pidfd needs to be overriden the following flags are added to
pidfd_send_signal():
- PIDFD_SIGNAL_THREAD
Send a thread-specific signal.
- PIDFD_SIGNAL_THREAD_GROUP
Send a thread-group directed signal.
- PIDFD_SIGNAL_PROCESS_GROUP
Send a process-group directed signal.
The scope change will only work if the struct pid is actually
used for this scope.
For example, in order to send a thread-group directed signal the
provided pidfd must be used as a thread-group leader and
similarly for PIDFD_SIGNAL_PROCESS_GROUP the struct pid must be
used as a process group leader.
- Move pidfds from the anonymous inode infrastructure to a tiny pseudo
filesystem. This will unblock further work that we weren't able to do
simply because of the very justified limitations of anonymous inodes.
Moving pidfds to a tiny pseudo filesystem allows for statx on pidfds
to become useful for the first time. They can now be compared by
inode number which are unique for the system lifetime.
Instead of stashing struct pid in file->private_data we can now stash
it in inode->i_private. This makes it possible to introduce concepts
that operate on a process once all file descriptors have been closed.
A concrete example is kill-on-last-close. Another side-effect is that
file->private_data is now freed up for per-file options for pidfds.
Now, each struct pid will refer to a different inode but the same
struct pid will refer to the same inode if it's opened multiple
times. In contrast to now where each struct pid refers to the same
inode.
The tiny pseudo filesystem is not visible anywhere in userspace
exactly like e.g., pipefs and sockfs. There's no lookup, there's no
complex inode operations, nothing. Dentries and inodes are always
deleted when the last pidfd is closed.
We allocate a new inode and dentry for each struct pid and we reuse
that inode and dentry for all pidfds that refer to the same struct
pid. The code is entirely optional and fairly small. If it's not
selected we fallback to anonymous inodes. Heavily inspired by nsfs.
The dentry and inode allocation mechanism is moved into generic
infrastructure that is now shared between nsfs and pidfs. The
path_from_stashed() helper must be provided with a stashing location,
an inode number, a mount, and the private data that is supposed to be
used and it will provide a path that can be passed to dentry_open().
The helper will try retrieve an existing dentry from the provided
stashing location. If a valid dentry is found it is reused. If not a
new one is allocated and we try to stash it in the provided location.
If this fails we retry until we either find an existing dentry or the
newly allocated dentry could be stashed. Subsequent openers of the
same namespace or task are then able to reuse it.
- Currently it is only possible to get notified when a task has exited,
i.e., become a zombie and userspace gets notified with EPOLLIN. We
now also support waiting until the task has been reaped, notifying
userspace with EPOLLHUP.
- Ensure that ESRCH is reported for getfd if a task is exiting instead
of the confusing EBADF.
- Various smaller cleanups to pidfd functions.
* tag 'vfs-6.9.pidfd' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits)
libfs: improve path_from_stashed()
libfs: add stashed_dentry_prune()
libfs: improve path_from_stashed() helper
pidfs: convert to path_from_stashed() helper
nsfs: convert to path_from_stashed() helper
libfs: add path_from_stashed()
pidfd: add pidfs
pidfd: move struct pidfd_fops
pidfd: allow to override signal scope in pidfd_send_signal()
pidfd: change pidfd_send_signal() to respect PIDFD_THREAD
signal: fill in si_code in prepare_kill_siginfo()
selftests: add ESRCH tests for pidfd_getfd()
pidfd: getfd should always report ESRCH if a task is exiting
pidfd: clone: allow CLONE_THREAD | CLONE_PIDFD together
pidfd: exit: kill the no longer used thread_group_exited()
pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN))
pid: kill the obsolete PIDTYPE_PID code in transfer_pid()
pidfd: kill the no longer needed do_notify_pidfd() in de_thread()
pidfd_poll: report POLLHUP when pid_task() == NULL
pidfd: implement PIDFD_THREAD flag for pidfd_open()
...
|
||
|
Linus Torvalds
|
97ec9715a8 |
Merge tag 'linux_kselftest-kunit-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull KUnit updates from Shuah Khan: - fix to make kunit_bus_type const - kunit tool change to Print UML command - DRM device creation helpers are now using the new kunit device creation helpers. This change resulted in DRM helpers switching from using a platform_device, to a dedicated bus and device type used by kunit. kunit devices don't set DMA mask and this caused regression on some drm tests as they can't allocate DMA buffers. Fix this problem by setting DMA masks on the kunit device during initialization. - KUnit has several macros which accept a log message, which can contain printf format specifiers. Some of these (the explicit log macros) already use the __printf() gcc attribute to ensure the format specifiers are valid, but those which could fail the test, and hence used __kunit_do_failed_assertion() behind the scenes, did not. These include: KUNIT_EXPECT_*_MSG(), KUNIT_ASSERT_*_MSG(), and KUNIT_FAIL() A nine-patch series adds the __printf() attribute, and fixes all of the issues uncovered. * tag 'linux_kselftest-kunit-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: kunit: Annotate _MSG assertion variants with gnu printf specifiers drm: tests: Fix invalid printf format specifiers in KUnit tests drm/xe/tests: Fix printf format specifiers in xe_migrate test net: test: Fix printf format specifier in skb_segment kunit test rtc: test: Fix invalid format specifier. time: test: Fix incorrect format specifier lib: memcpy_kunit: Fix an invalid format specifier in an assertion msg lib/cmdline: Fix an invalid format specifier in an assertion msg kunit: test: Log the correct filter string in executor_test kunit: Setup DMA masks on the kunit device kunit: make kunit_bus_type const kunit: Mark filter* params as rw kunit: tool: Print UML command |
||
|
Linus Torvalds
|
fa4b851b4a |
Merge tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt: - Do not allow large strings (> 4096) as single write to trace_marker The size of a string written into trace_marker was determined by the size of the sub-buffer in the ring buffer. That size is dependent on the PAGE_SIZE of the architecture as it can be mapped into user space. But on PowerPC, where PAGE_SIZE is 64K, that made the limit of the string of writing into trace_marker 64K. One of the selftests looks at the size of the ring buffer sub-buffers and writes that plus more into the trace_marker. The write will take what it can and report back what it consumed so that the user space application (like echo) will write the rest of the string. The string is stored in the ring buffer and can be read via the "trace" or "trace_pipe" files. The reading of the ring buffer uses vsnprintf(), which uses a precision "%.*s" to make sure it only reads what is stored in the buffer, as a bug could cause the string to be non terminated. With the combination of the precision change and the PAGE_SIZE of 64K allowing huge strings to be added into the ring buffer, plus the test that would actually stress that limit, a bug was reported that the precision used was too big for "%.*s" as the string was close to 64K in size and the max precision of vsnprintf is 32K. Linus suggested not to have that precision as it could hide a bug if the string was again stored without a nul byte. Another issue that was brought up is that the trace_seq buffer is also based on PAGE_SIZE even though it is not tied to the architecture limit like the ring buffer sub-buffer is. Having it be 64K * 2 is simply just too big and wasting memory on systems with 64K page sizes. It is now hardcoded to 8K which is what all other architectures with 4K PAGE_SIZE has. Finally, the write to trace_marker is now limited to 4K as there is no reason to write larger strings into trace_marker. - ring_buffer_wait() should not loop. The ring_buffer_wait() does not have the full context (yet) on if it should loop or not. Just exit the loop as soon as its woken up and let the callers decide to loop or not (they already do, so it's a bit redundant). - Fix shortest_full field to be the smallest amount in the ring buffer that a waiter is waiting for. The "shortest_full" field is updated when a new waiter comes in and wants to wait for a smaller amount of data in the ring buffer than other waiters. But after all waiters are woken up, it's not reset, so if another waiter comes in wanting to wait for more data, it will be woken up when the ring buffer has a smaller amount from what the previous waiters were waiting for. - The wake up all waiters on close is incorrectly called frome .release() and not from .flush() so it will never wake up any waiters as the .release() will not get called until all .read() calls are finished. And the wakeup is for the waiters in those .read() calls. * tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use .flush() call to wake up readers ring-buffer: Fix resetting of shortest_full ring-buffer: Fix waking up ring buffer readers tracing: Limit trace_marker writes to just 4K tracing: Limit trace_seq size to just 8K and not depend on architecture PAGE_SIZE tracing: Remove precision vsnprintf() check from print event |
||
|
Steven Rostedt (Google)
|
e5d7c19165 |
tracing: Use .flush() call to wake up readers
The .release() function does not get called until all readers of a file
descriptor are finished.
If a thread is blocked on reading a file descriptor in ring_buffer_wait(),
and another thread closes the file descriptor, it will not wake up the
other thread as ring_buffer_wake_waiters() is called by .release(), and
that will not get called until the .read() is finished.
The issue originally showed up in trace-cmd, but the readers are actually
other processes with their own file descriptors. So calling close() would wake
up the other tasks because they are blocked on another descriptor then the
one that was closed(). But there's other wake ups that solve that issue.
When a thread is blocked on a read, it can still hang even when another
thread closed its descriptor.
This is what the .flush() callback is for. Have the .flush() wake up the
readers.
Link: https://lore.kernel.org/linux-trace-kernel/20240308202432.107909457@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
|
Steven Rostedt (Google)
|
68282dd930 |
ring-buffer: Fix resetting of shortest_full
The "shortest_full" variable is used to keep track of the waiter that is
waiting for the smallest amount on the ring buffer before being woken up.
When a tasks waits on the ring buffer, it passes in a "full" value that is
a percentage. 0 means wake up on any data. 1-100 means wake up from 1% to
100% full buffer.
As all waiters are on the same wait queue, the wake up happens for the
waiter with the smallest percentage.
The problem is that the smallest_full on the cpu_buffer that stores the
smallest amount doesn't get reset when all the waiters are woken up. It
does get reset when the ring buffer is reset (echo > /sys/kernel/tracing/trace).
This means that tasks may be woken up more often then when they want to
be. Instead, have the shortest_full field get reset just before waking up
all the tasks. If the tasks wait again, they will update the shortest_full
before sleeping.
Also add locking around setting of shortest_full in the poll logic, and
change "work" to "rbwork" to match the variable name for rb_irq_work
structures that are used in other places.
Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.948914369@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
|
Steven Rostedt (Google)
|
b359457368 |
ring-buffer: Fix waking up ring buffer readers
A task can wait on a ring buffer for when it fills up to a specific
watermark. The writer will check the minimum watermark that waiters are
waiting for and if the ring buffer is past that, it will wake up all the
waiters.
The waiters are in a wait loop, and will first check if a signal is
pending and then check if the ring buffer is at the desired level where it
should break out of the loop.
If a file that uses a ring buffer closes, and there's threads waiting on
the ring buffer, it needs to wake up those threads. To do this, a
"wait_index" was used.
Before entering the wait loop, the waiter will read the wait_index. On
wakeup, it will check if the wait_index is different than when it entered
the loop, and will exit the loop if it is. The waker will only need to
update the wait_index before waking up the waiters.
This had a couple of bugs. One trivial one and one broken by design.
The trivial bug was that the waiter checked the wait_index after the
schedule() call. It had to be checked between the prepare_to_wait() and
the schedule() which it was not.
The main bug is that the first check to set the default wait_index will
always be outside the prepare_to_wait() and the schedule(). That's because
the ring_buffer_wait() doesn't have enough context to know if it should
break out of the loop.
The loop itself is not needed, because all the callers to the
ring_buffer_wait() also has their own loop, as the callers have a better
sense of what the context is to decide whether to break out of the loop
or not.
Just have the ring_buffer_wait() block once, and if it gets woken up, exit
the function and let the callers decide what to do next.
Link: https://lore.kernel.org/all/CAHk-=whs5MdtNjzFkTyaUy=vHi=qwWgPi0JgTe6OYUYMNSRZfg@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.792933613@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes:
|
||
|
Linus Torvalds
|
df4793505a |
Merge tag 'net-6.8-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from bpf, ipsec and netfilter.
No solution yet for the stmmac issue mentioned in the last PR, but it
proved to be a lockdep false positive, not a blocker.
Current release - regressions:
- dpll: move all dpll<>netdev helpers to dpll code, fix build
regression with old compilers
Current release - new code bugs:
- page_pool: fix netlink dump stop/resume
Previous releases - regressions:
- bpf: fix verifier to check bpf_func_state->callback_depth when
pruning states as otherwise unsafe programs could get accepted
- ipv6: avoid possible UAF in ip6_route_mpath_notify()
- ice: reconfig host after changing MSI-X on VF
- mlx5:
- e-switch, change flow rule destination checking
- add a memory barrier to prevent a possible null-ptr-deref
- switch to using _bh variant of of spinlock where needed
Previous releases - always broken:
- netfilter: nf_conntrack_h323: add protection for bmp length out of
range
- bpf: fix to zero-initialise xdp_rxq_info struct before running XDP
program in CPU map which led to random xdp_md fields
- xfrm: fix UDP encapsulation in TX packet offload
- netrom: fix data-races around sysctls
- ice:
- fix potential NULL pointer dereference in ice_bridge_setlink()
- fix uninitialized dplls mutex usage
- igc: avoid returning frame twice in XDP_REDIRECT
- i40e: disable NAPI right after disabling irqs when handling
xsk_pool
- geneve: make sure to pull inner header in geneve_rx()
- sparx5: fix use after free inside sparx5_del_mact_entry
- dsa: microchip: fix register write order in ksz8_ind_write8()
Misc:
- selftests: mptcp: fixes for diag.sh"
* tag 'net-6.8-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (63 commits)
net: pds_core: Fix possible double free in error handling path
netrom: Fix data-races around sysctl_net_busy_read
netrom: Fix a data-race around sysctl_netrom_link_fails_count
netrom: Fix a data-race around sysctl_netrom_routing_control
netrom: Fix a data-race around sysctl_netrom_transport_no_activity_timeout
netrom: Fix a data-race around sysctl_netrom_transport_requested_window_size
netrom: Fix a data-race around sysctl_netrom_transport_busy_delay
netrom: Fix a data-race around sysctl_netrom_transport_acknowledge_delay
netrom: Fix a data-race around sysctl_netrom_transport_maximum_tries
netrom: Fix a data-race around sysctl_netrom_transport_timeout
netrom: Fix data-races around sysctl_netrom_network_ttl_initialiser
netrom: Fix a data-race around sysctl_netrom_obsolescence_count_initialiser
netrom: Fix a data-race around sysctl_netrom_default_path_quality
netfilter: nf_conntrack_h323: Add protection for bmp length out of range
netfilter: nf_tables: mark set as dead when unbinding anonymous set with timeout
netfilter: nft_ct: fix l3num expectations with inet pseudo family
netfilter: nf_tables: reject constant set with timeout
netfilter: nf_tables: disallow anonymous set with timeout flag
net/rds: fix WARNING in rds_conn_connect_if_down
net: dsa: microchip: fix register write order in ksz8_ind_write8()
...
|
||
|
Steven Rostedt (Google)
|
095fe48912 |
tracing: Limit trace_marker writes to just 4K
Limit the max print event of trace_marker to just 4K string size. This must also be less than the amount that can be held by a trace_seq along with the text that is before the output (like the task name, PID, CPU, state, etc). As trace_seq is made to handle large events (some greater than 4K). Make the max size of a trace_marker write event be 4K which is guaranteed to fit in the trace_seq buffer. Link: https://lore.kernel.org/linux-trace-kernel/20240304223433.4ba47dff@gandalf.local.home Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt (Google)
|
5efd3e2aef |
tracing: Remove precision vsnprintf() check from print event
This reverts |
||
|
Frederic Weisbecker
|
8ca1836769 |
timer/migration: Fix quick check reporting late expiry
When a CPU is the last active in the hierarchy and it tries to enter
into idle, the quick check looking up the next event towards cpuidle
heuristics may report a too late expiry, such as in the following
scenario:
[GRP1:0]
migrator = NONE
active = NONE
nextevt = T0:0, T0:1
/ \
[GRP0:0] [GRP0:1]
migrator = NONE migrator = NONE
active = NONE active = NONE
nextevt = T0, T1 nextevt = T2
/ \ / \
0 1 2 3
idle idle idle idle
0) The whole system is idle, and CPU 0 was the last migrator. CPU 0 has
a timer (T0), CPU 1 has a timer (T1) and CPU 2 has a timer (T2). The
expire order is T0 < T1 < T2.
[GRP1:0]
migrator = GRP0:0
active = GRP0:0
nextevt = T0:0(i), T0:1
/ \
[GRP0:0] [GRP0:1]
migrator = CPU0 migrator = NONE
active = CPU0 active = NONE
nextevt = T0(i), T1 nextevt = T2
/ \ / \
0 1 2 3
active idle idle idle
1) CPU 0 becomes active. The (i) means a now ignored timer.
[GRP1:0]
migrator = GRP0:0
active = GRP0:0
nextevt = T0:1
/ \
[GRP0:0] [GRP0:1]
migrator = CPU0 migrator = NONE
active = CPU0 active = NONE
nextevt = T1 nextevt = T2
/ \ / \
0 1 2 3
active idle idle idle
2) CPU 0 handles remote. No timer actually expired but ignored timers
have been cleaned out and their sibling's timers haven't been
propagated. As a result the top level's next event is T2 and not T1.
3) CPU 0 tries to enter idle without any global timer enqueued and calls
tmigr_quick_check(). The expiry of T2 is returned instead of the
expiry of T1.
When the quick check returns an expiry that is too late, the cpuidle
governor may pick up a C-state that is too deep. This may be result into
undesired CPU wake up latency if the next timer is actually close enough.
Fix this with assuming that expiries aren't sorted top-down while
performing the quick check. Pick up instead the earliest encountered one
while walking up the hierarchy.
|
||
|
Toke Høiland-Jørgensen
|
2487007aa3 |
cpumap: Zero-initialise xdp_rxq_info struct before running XDP program
When running an XDP program that is attached to a cpumap entry, we don't
initialise the xdp_rxq_info data structure being used in the xdp_buff
that backs the XDP program invocation. Tobias noticed that this leads to
random values being returned as the xdp_md->rx_queue_index value for XDP
programs running in a cpumap.
This means we're basically returning the contents of the uninitialised
memory, which is bad. Fix this by zero-initialising the rxq data
structure before running the XDP program.
Fixes:
|
||
|
Eduard Zingerman
|
e9a8e5a587 |
bpf: check bpf_func_state->callback_depth when pruning states
When comparing current and cached states verifier should consider
bpf_func_state->callback_depth. Current state cannot be pruned against
cached state, when current states has more iterations left compared to
cached state. Current state has more iterations left when it's
callback_depth is smaller.
Below is an example illustrating this bug, minimized from mailing list
discussion [0] (assume that BPF_F_TEST_STATE_FREQ is set).
The example is not a safe program: if loop_cb point (1) is followed by
loop_cb point (2), then division by zero is possible at point (4).
struct ctx {
__u64 a;
__u64 b;
__u64 c;
};
static void loop_cb(int i, struct ctx *ctx)
{
/* assume that generated code is "fallthrough-first":
* if ... == 1 goto
* if ... == 2 goto
* <default>
*/
switch (bpf_get_prandom_u32()) {
case 1: /* 1 */ ctx->a = 42; return 0; break;
case 2: /* 2 */ ctx->b = 42; return 0; break;
default: /* 3 */ ctx->c = 42; return 0; break;
}
}
SEC("tc")
__failure
__flag(BPF_F_TEST_STATE_FREQ)
int test(struct __sk_buff *skb)
{
struct ctx ctx = { 7, 7, 7 };
bpf_loop(2, loop_cb, &ctx, 0); /* 0 */
/* assume generated checks are in-order: .a first */
if (ctx.a == 42 && ctx.b == 42 && ctx.c == 7)
asm volatile("r0 /= 0;":::"r0"); /* 4 */
return 0;
}
Prior to this commit verifier built the following checkpoint tree for
this example:
.------------------------------------- Checkpoint / State name
| .-------------------------------- Code point number
| | .---------------------------- Stack state {ctx.a,ctx.b,ctx.c}
| | | .------------------- Callback depth in frame #0
v v v v
- (0) {7P,7P,7},depth=0
- (3) {7P,7P,7},depth=1
- (0) {7P,7P,42},depth=1
- (3) {7P,7,42},depth=2
- (0) {7P,7,42},depth=2 loop terminates because of depth limit
- (4) {7P,7,42},depth=0 predicted false, ctx.a marked precise
- (6) exit
(a) - (2) {7P,7,42},depth=2
- (0) {7P,42,42},depth=2 loop terminates because of depth limit
- (4) {7P,42,42},depth=0 predicted false, ctx.a marked precise
- (6) exit
(b) - (1) {7P,7P,42},depth=2
- (0) {42P,7P,42},depth=2 loop terminates because of depth limit
- (4) {42P,7P,42},depth=0 predicted false, ctx.{a,b} marked precise
- (6) exit
- (2) {7P,7,7},depth=1 considered safe, pruned using checkpoint (a)
(c) - (1) {7P,7P,7},depth=1 considered safe, pruned using checkpoint (b)
Here checkpoint (b) has callback_depth of 2, meaning that it would
never reach state {42,42,7}.
While checkpoint (c) has callback_depth of 1, and thus
could yet explore the state {42,42,7} if not pruned prematurely.
This commit makes forbids such premature pruning,
allowing verifier to explore states sub-tree starting at (c):
(c) - (1) {7,7,7P},depth=1
- (0) {42P,7,7P},depth=1
...
- (2) {42,7,7},depth=2
- (0) {42,42,7},depth=2 loop terminates because of depth limit
- (4) {42,42,7},depth=0 predicted true, ctx.{a,b,c} marked precise
- (5) division by zero
[0] https://lore.kernel.org/bpf/9b251840-7cb8-4d17-bd23-1fc8071d8eef@linux.dev/
Fixes:
|
||
|
Linus Torvalds
|
5847c9777c |
Merge tag 'cgroup-for-6.8-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo: "Two cpuset fixes. Both are for bugs in error handling paths and low risk" * tag 'cgroup-for-6.8-rc7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup/cpuset: Fix retval in update_cpumask() cgroup/cpuset: Fix a memory leak in update_exclusive_cpumask() |
||
|
Linus Torvalds
|
161671a6eb |
Merge tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull fprobe fix from Masami Hiramatsu: - allocate entry_data_size buffer for each rethook instance. This fixes a buffer overrun bug (which leads a kernel crash) when fprobe user uses its entry_data in the entry_handler. * tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: fprobe: Fix to allocate entry_data_size buffer with rethook instances |
||
|
Christian Brauner
|
b28ddcc32d |
pidfs: convert to path_from_stashed() helper
Moving pidfds from the anonymous inode infrastructure to a separate tiny in-kernel filesystem similar to sockfs, pipefs, and anon_inodefs causes selinux denials and thus various userspace components that make heavy use of pidfds to fail as pidfds used anon_inode_getfile() which aren't subject to any LSM hooks. But dentry_open() is and that would cause regressions. The failures that are seen are selinux denials. But the core failure is dbus-broker. That cascades into other services failing that depend on dbus-broker. For example, when dbus-broker fails to start polkit and all the others won't be able to work because they depend on dbus-broker. The reason for dbus-broker failing is because it doesn't handle failures for SO_PEERPIDFD correctly. Last kernel release we introduced SO_PEERPIDFD (and SCM_PIDFD). SO_PEERPIDFD allows dbus-broker and polkit and others to receive a pidfd for the peer of an AF_UNIX socket. This is the first time in the history of Linux that we can safely authenticate clients in a race-free manner. dbus-broker immediately made use of this but messed up the error checking. It only allowed EINVAL as a valid failure for SO_PEERPIDFD. That's obviously problematic not just because of LSM denials but because of seccomp denials that would prevent SO_PEERPIDFD from working; or any other new error code from there. So this is catching a flawed implementation in dbus-broker as well. It has to fallback to the old pid-based authentication when SO_PEERPIDFD doesn't work no matter the reasons otherwise it'll always risk such failures. So overall that LSM denial should not have caused dbus-broker to fail. It can never assume that a feature released one kernel ago like SO_PEERPIDFD can be assumed to be available. So, the next fix separate from the selinux policy update is to try and fix dbus-broker at [3]. That should make it into Fedora as well. In addition the selinux reference policy should also be updated. See [4] for that. If Selinux is in enforcing mode in userspace and it encounters anything that it doesn't know about it will deny it by default. And the policy is entirely in userspace including declaring new types for stuff like nsfs or pidfs to allow it. For now we continue to raise S_PRIVATE on the inode if it's a pidfs inode which means things behave exactly like before. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2265630 Link: https://github.com/fedora-selinux/selinux-policy/pull/2050 Link: https://github.com/bus1/dbus-broker/pull/343 [3] Link: https://github.com/SELinuxProject/refpolicy/pull/762 [4] Reported-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240222190334.GA412503@dev-arch.thelio-3990X Link: https://lore.kernel.org/r/20240218-neufahrzeuge-brauhaus-fb0eb6459771@brauner Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
Christian Brauner
|
cb12fd8e0d |
pidfd: add pidfs
This moves pidfds from the anonymous inode infrastructure to a tiny pseudo filesystem. This has been on my todo for quite a while as it will unblock further work that we weren't able to do simply because of the very justified limitations of anonymous inodes. Moving pidfds to a tiny pseudo filesystem allows: * statx() on pidfds becomes useful for the first time. * pidfds can be compared simply via statx() and then comparing inode numbers. * pidfds have unique inode numbers for the system lifetime. * struct pid is now stashed in inode->i_private instead of file->private_data. This means it is now possible to introduce concepts that operate on a process once all file descriptors have been closed. A concrete example is kill-on-last-close. * file->private_data is freed up for per-file options for pidfds. * Each struct pid will refer to a different inode but the same struct pid will refer to the same inode if it's opened multiple times. In contrast to now where each struct pid refers to the same inode. Even if we were to move to anon_inode_create_getfile() which creates new inodes we'd still be associating the same struct pid with multiple different inodes. The tiny pseudo filesystem is not visible anywhere in userspace exactly like e.g., pipefs and sockfs. There's no lookup, there's no complex inode operations, nothing. Dentries and inodes are always deleted when the last pidfd is closed. We allocate a new inode for each struct pid and we reuse that inode for all pidfds. We use iget_locked() to find that inode again based on the inode number which isn't recycled. We allocate a new dentry for each pidfd that uses the same inode. That is similar to anonymous inodes which reuse the same inode for thousands of dentries. For pidfds we're talking way less than that. There usually won't be a lot of concurrent openers of the same struct pid. They can probably often be counted on two hands. I know that systemd does use separate pidfd for the same struct pid for various complex process tracking issues. So I think with that things actually become way simpler. Especially because we don't have to care about lookup. Dentries and inodes continue to be always deleted. The code is entirely optional and fairly small. If it's not selected we fallback to anonymous inodes. Heavily inspired by nsfs which uses a similar stashing mechanism just for namespaces. Link: https://lore.kernel.org/r/20240213-vfs-pidfd_fs-v1-2-f863f58cfce1@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
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Masami Hiramatsu (Google)
|
6572786006 |
fprobe: Fix to allocate entry_data_size buffer with rethook instances
Fix to allocate fprobe::entry_data_size buffer with rethook instances.
If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
fprobe entry handler can cause a buffer overrun when storing entry data in
entry handler.
Link: https://lore.kernel.org/all/170920576727.107552.638161246679734051.stgit@devnote2/
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/Zd9eBn2FTQzYyg7L@krava/
Fixes:
|
||
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Tejun Heo
|
1acd92d95f |
workqueue: Drain BH work items on hot-unplugged CPUs
Boqun pointed out that workqueues aren't handling BH work items on offlined CPUs. Unlike tasklet which transfers out the pending tasks from CPUHP_SOFTIRQ_DEAD, BH workqueue would just leave them pending which is problematic. Note that this behavior is specific to BH workqueues as the non-BH per-CPU workers just become unbound when the CPU goes offline. This patch fixes the issue by draining the pending BH work items from an offlined CPU from CPUHP_SOFTIRQ_DEAD. Because work items carry more context, it's not as easy to transfer the pending work items from one pool to another. Instead, run BH work items which execute the offlined pools on an online CPU. Note that this assumes that no further BH work items will be queued on the offlined CPUs. This assumption is shared with tasklet and should be fine for conversions. However, this issue also exists for per-CPU workqueues which will just keep executing work items queued after CPU offline on unbound workers and workqueue should reject per-CPU and BH work items queued on offline CPUs. This will be addressed separately later. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: http://lkml.kernel.org/r/Zdvw0HdSXcU3JZ4g@boqun-archlinux |
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Kamalesh Babulal
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25125a4762 |
cgroup/cpuset: Fix retval in update_cpumask()
The update_cpumask(), checks for newly requested cpumask by calling
validate_change(), which returns an error on passing an invalid set
of cpu(s). Independent of the error returned, update_cpumask() always
returns zero, suppressing the error and returning success to the user
on writing an invalid cpu range for a cpuset. Fix it by returning
retval instead, which is returned by validate_change().
Fixes:
|
||
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Xiongwei Song
|
3ab67a9ce8 |
cgroup/cpuset: Mark memory_spread_slab as obsolete
We've removed the SLAB allocator, cpuset_do_slab_mem_spread() and SLAB_MEM_SPREAD, memory_spread_slab is a no-op now. We can mark memory_spread_slab as obsolete in case someone still wants to use it after cpuset_do_slab_mem_spread() removed. For more details, please check [1]. [1] https://lore.kernel.org/lkml/32bc1403-49da-445a-8c00-9686a3b0d6a3@redhat.com/T/#m8e292e21b00f95a4bb8086371fa7387fa4ea8f60 tj: Description and cosmetic updates. Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> |
||
|
Arnd Bergmann
|
a184d9835a |
tick/sched: Fix build failure for CONFIG_NO_HZ_COMMON=n
In configurations with CONFIG_TICK_ONESHOT but no CONFIG_NO_HZ or
CONFIG_HIGH_RES_TIMERS, tick_sched_timer_dying() is stubbed out,
but still defined as a global function as well:
kernel/time/tick-sched.c:1599:6: error: redefinition of 'tick_sched_timer_dying'
1599 | void tick_sched_timer_dying(int cpu)
| ^
kernel/time/tick-sched.h:111:20: note: previous definition is here
111 | static inline void tick_sched_timer_dying(int cpu) { }
| ^
This configuration only appears with ARM CONFIG_ARCH_BCM_MOBILE,
which should not actually select CONFIG_TICK_ONESHOT.
Adjust the #ifdef for the stub to match the condition for building the
tick-sched.c file for consistency with the definition and to avoid
the build regression.
Fixes:
|
||
|
Waiman Long
|
66f40b926d |
cgroup/cpuset: Fix a memory leak in update_exclusive_cpumask()
Fix a possible memory leak in update_exclusive_cpumask() by moving the
alloc_cpumasks() down after the validate_change() check which can fail
and still before the temporary cpumasks are needed.
Fixes:
|
||
|
Christian Brauner
|
50f4f2d197 |
pidfd: move struct pidfd_fops
Move the pidfd file operations over to their own file in preparation of implementing pidfs and to isolate them from other mostly unrelated functionality in other files. Link: https://lore.kernel.org/r/20240213-vfs-pidfd_fs-v1-1-f863f58cfce1@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org> |
||
|
David Gow
|
133e267ef4 |
time: test: Fix incorrect format specifier
'days' is a s64 (from div_s64), and so should use a %lld specifier.
This was found by extending KUnit's assertion macros to use gcc's
__printf attribute.
Fixes:
|
||
|
Ingo Molnar
|
9b9c280b9a |
Merge branch 'x86/urgent' into x86/apic, to resolve conflicts
Conflicts: arch/x86/kernel/cpu/common.c arch/x86/kernel/cpu/intel.c Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
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Ingo Molnar
|
4c8a498541 |
smp: Avoid 'setup_max_cpus' namespace collision/shadowing
bringup_nonboot_cpus() gets passed the 'setup_max_cpus' variable in init/main.c - which is also the name of the parameter, shadowing the name. To reduce confusion and to allow the 'setup_max_cpus' value to be #defined in the <linux/smp.h> header, use the 'max_cpus' name for the function parameter name. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org |
||
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Boqun Feng
|
3add00be5f | Merge branches 'rcu-doc.2024.02.14a', 'rcu-nocb.2024.02.14a', 'rcu-exp.2024.02.14a', 'rcu-tasks.2024.02.26a' and 'rcu-misc.2024.02.14a' into rcu.2024.02.26a | ||
|
Frederic Weisbecker
|
19b344a91f |
timers: Assert no next dyntick timer look-up while CPU is offline
The next timer (re-)evaluation, with the purpose of entering/updating the dyntick mode, can happen from 3 sites and none of them are relevant while the CPU is offline: 1) The idle loop: a) From the quick check helping the cpuidle governor to heuristically predict the best C-state. b) While stopping the tick. But if the CPU is offline, the tick has been cancelled and there is consequently no need to further stop the tick. 2) Remote expiry: when a CPU remotely expires global timers on behalf of another CPU, the latter target's next timer is re-evaluated afterwards. However remote expîry doesn't happen on offline CPUs. 3) IRQ exit: on nohz_full mode, the tick is (re-)evaluated on IRQ exit. But full dynticks is disabled on offline CPUs. Therefore it is safe to assume that no next dyntick timer lookup can be performed on offline CPUs. Assert this expectation to report any surprise. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-17-frederic@kernel.org |
||
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Frederic Weisbecker
|
500f8f9bce |
tick: Assume timekeeping is correctly handed over upon last offline idle call
The timekeeping duty is handed over from the outgoing CPU on stop machine, then the oneshot tick is stopped right after. Therefore it's guaranteed that the current CPU isn't the timekeeper upon its last call to idle. Besides, calling tick_nohz_idle_stop_tick() while the dying CPU goes into idle suggests that the tick is going to be stopped while it is actually stopped already from the appropriate CPU hotplug state. Remove the confusing call and the obsolete case handling and convert it to a sanity check that verifies the above assumption. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-16-frederic@kernel.org |
||
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Frederic Weisbecker
|
3f69d04e14 |
tick: Shut down low-res tick from dying CPU
The timekeeping duty is handed over from the outgoing CPU within stop machine. This works well if CONFIG_NO_HZ_COMMON=n or the tick is in high-res mode. However in low-res dynticks mode, the tick isn't cancelled until the clockevent is shut down, which can happen later. The tick may therefore fire again once IRQs are re-enabled on stop machine and until IRQs are disabled for good upon the last call to idle. That's so many opportunities for a timekeeper to go idle and the outgoing CPU to take over that duty. This is why tick_nohz_idle_stop_tick() is called one last time on idle if the CPU is seen offline: so that the timekeeping duty is handed over again in case the CPU has re-taken the duty. This means there are two timekeeping handovers on CPU down hotplug with different undocumented constraints and purposes: 1) A handover on stop machine for !dynticks || highres. All online CPUs are guaranteed to be non-idle and the timekeeping duty can be safely handed-over. The hrtimer tick is cancelled so it is guaranteed that in dynticks mode the outgoing CPU won't take again the duty. 2) A handover on last idle call for dynticks && lowres. Setting the duty to TICK_DO_TIMER_NONE makes sure that a CPU will take over the timekeeping. Prepare for consolidating the handover to a single place (the first one) with shutting down the low-res tick as well from tick_cancel_sched_timer() as well. This will simplify the handover and unify the tick cancellation between high-res and low-res. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-15-frederic@kernel.org |
||
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Frederic Weisbecker
|
7988e5ae2b |
tick: Split nohz and highres features from nohz_mode
The nohz mode field tells about low resolution nohz mode or high resolution nohz mode but it doesn't tell about high resolution non-nohz mode. In order to retrieve the latter state, tick_cancel_sched_timer() must fiddle with struct hrtimer's internals to guess if the tick has been initialized in high resolution. Move instead the nohz mode field information into the tick flags and provide two new bits: one to know if the tick is in nohz mode and another one to know if the tick is in high resolution. The combination of those two flags provides all the needed informations to determine which of the three tick modes is running. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-14-frederic@kernel.org |
||
|
Frederic Weisbecker
|
a478ffb2ae |
tick: Move individual bit features to debuggable mask accesses
The individual bitfields of struct tick_sched must be modified from IRQs disabled places, otherwise local modifications can race due to them sharing the same memory storage. The recent move of the "got_idle_tick" bitfield to its own storage shows that the use of these bitfields, as pretty as they look, can be as much error prone. In order to avoid future issues of the like and make sure that those bitfields are safely accessed, move those flags to an explicit mask along with a mutator function performing the basic IRQs disabled sanity check. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-13-frederic@kernel.org |
||
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Frederic Weisbecker
|
3ce74f1a85 |
tick: Move got_idle_tick away from common flags
tick_nohz_idle_got_tick() is called by cpuidle_reflect() within the idle loop with interrupts enabled. This function modifies the struct tick_sched's bitfield "got_idle_tick". However this bitfield is stored within the same mask as other bitfields that can be modified from interrupts. Fortunately so far it looks like the only race that can happen is while writing ->got_idle_tick to 0, an interrupt fires and writes the ->idle_active field to 0. It's then possible that the interrupted write to ->got_idle_tick writes back the old value of ->idle_active back to 1. However if that happens, the worst possible outcome is that the time spent between that interrupt and the upcoming call to tick_nohz_idle_exit() is accounted as idle, which is negligible quantity. Still all the bitfield writes within this struct tick_sched's shadow mask should be IRQ-safe. Therefore move this bitfield out to its own storage to avoid further suprises. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-12-frederic@kernel.org |
||
|
Frederic Weisbecker
|
d9b1865c86 |
tick: Assume the tick can't be stopped in NOHZ_MODE_INACTIVE mode
The full-nohz update function checks if the nohz mode is active before proceeding. It considers one exception though: if the tick is already stopped even though the nohz mode is inactive, it still moves on in order to update/restart the tick if needed. However in order for the tick to be stopped, the nohz_mode has to be either NOHZ_MODE_LOWRES or NOHZ_MODE_HIGHRES. Therefore it doesn't make sense to test if the tick is stopped before verifying NOHZ_MODE_INACTIVE mode. Remove the needless related condition. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-11-frederic@kernel.org |
||
|
Frederic Weisbecker
|
ef8969bb55 |
tick: Move broadcast cancellation up to CPUHP_AP_TICK_DYING
The broadcast shutdown code is executed through a random explicit call within stop machine from the outgoing CPU. However the tick broadcast is a midware between the tick callback and the clocksource, therefore it makes more sense to shut it down after the tick callback and before the clocksource drivers. Move it instead to the common tick shutdown CPU hotplug state where related operations can be ordered from highest to lowest level. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-10-frederic@kernel.org |
||
|
Frederic Weisbecker
|
f04e51220a |
tick: Move tick cancellation up to CPUHP_AP_TICK_DYING
The tick hrtimer is cancelled right before hrtimers are migrated. This is done from the hrtimer subsystem even though it shouldn't know about its actual users. Move instead the tick hrtimer cancellation to the relevant CPU hotplug state that aims at centralizing high level tick shutdown operations so that the related flow is easy to follow. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-9-frederic@kernel.org |
||
|
Frederic Weisbecker
|
3ad6eb0683 |
tick: Start centralizing tick related CPU hotplug operations
During the CPU offlining process, the various timer tick features are
shut down from scattered places, sometimes from teardown callbacks on
stop machine, sometimes through explicit calls, sometimes from the
control CPU after the CPU died. The reason why these shutdown operations
are spread around is not always clear and it makes the tick lifecycle
hard to follow.
The tick should be shut down in order from highest to lowest level:
On stop machine from the dying CPU (high-level):
1) Hand-over the timekeeping duty (tick_handover_do_timer())
2) Cancel the tick implementation called by the clockevent callback
(tick_cancel_sched_timer())
3) Shutdown broadcasting (tick_offline_cpu() / tick_broadcast_offline())
On stop machine from the dying CPU (low-level):
4) Shutdown clockevents drivers (CPUHP_AP_*_TIMER_STARTING states)
From the control CPU after the CPU died (low-level):
5) Shutdown/unregister/cleanup clockevents for the dead CPU
(tick_cleanup_dead_cpu())
Instead the current order is 2, 4 (both from CPU hotplug states), then
1 and 3 through direct calls. This layout and order don't make much
sense. The operations 1, 2, 3 should be gathered together and in order.
Sort this situation with creating a new TICK shut-down CPU hotplug state
and start with introducing the timekeeping duty hand-over there. The
state must precede hrtimers migration because the tick hrtimer will be
stopped from it in a further patch.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240225225508.11587-8-frederic@kernel.org
|
||
|
Frederic Weisbecker
|
60313c21c3 |
tick/sched: Don't clear ts::next_tick again in can_stop_idle_tick()
The tick sched structure is already cleared from tick_cancel_sched_timer(), so there is no need to clear that field again. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240225225508.11587-7-frederic@kernel.org |