ttwu_do_activate() is used for a complete wakeup, in which we will
activate_task() and use ttwu_do_wakeup() to mark the task runnable
and perform wakeup-preemption, also call class->task_woken() callback
and update the rq->idle_stamp.
Since ttwu_runnable() is not a complete wakeup, don't need all those
done in ttwu_do_wakeup(), so we can move those to ttwu_do_activate()
to simplify ttwu_do_wakeup(), making it only mark the task runnable
to be reused in ttwu_runnable() and try_to_wake_up().
This patch should not have any functional changes.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20221223103257.4962-2-zhouchengming@bytedance.com
ttwu_runnable() is used as a fast wakeup path when the wakee task
is running on CPU or runnable on RQ, in both cases we can just
set its state to TASK_RUNNING to prevent a sleep.
If the wakee task is on_cpu running, we don't need to update_rq_clock()
or check_preempt_curr().
But if the wakee task is on_rq && !on_cpu (e.g. an IRQ hit before
the task got to schedule() and the task been preempted), we should
check_preempt_curr() to see if it can preempt the current running.
This also removes the class->task_woken() callback from ttwu_runnable(),
which wasn't required per the RT/DL implementations: any required push
operation would have been queued during class->set_next_task() when p
got preempted.
ttwu_runnable() also loses the update to rq->idle_stamp, as by definition
the rq cannot be idle in this scenario.
Suggested-by: Valentin Schneider <vschneid@redhat.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20221223103257.4962-1-zhouchengming@bytedance.com
When select_idle_capacity() starts scanning for an idle CPU, it starts
with target CPU that has already been checked in select_idle_sibling().
So we start checking from the next CPU and try the target CPU at the end.
Similarly for task_numa_assign(), we have just checked numa_migrate_on
of dst_cpu, so start from the next CPU. This also works for
steal_cookie_task(), the first scan must fail and start directly
from the next one.
Signed-off-by: Hao Jia <jiahao.os@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20221216062406.7812-3-jiahao.os@bytedance.com
In update_numa_stats() we try to find an idle cpu on the NUMA node,
preferably an idle core. we can stop looking for the next idle core
or idle cpu after finding an idle core. But we can't stop the
whole loop of scanning the CPU, because we need to calculate
approximate NUMA stats at a point in time. For example,
the src and dst nr_running is needed by task_numa_find_cpu().
Signed-off-by: Hao Jia <jiahao.os@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20221216062406.7812-2-jiahao.os@bytedance.com
With a modified container_of() that preserves constness, the compiler
finds some pointers which should have been marked as const. task_of()
also needs to become const-preserving for the !FAIR_GROUP_SCHED case so
that cfs_rq_of() can take a const argument. No change to generated code.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221212144946.2657785-1-willy@infradead.org
Introduce a rseq-x86-bits.h template header which is internally included
to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
This introduces changes to the rseq.h selftests API which require to
update the rseq selftest programs. Similar API/templating changes need
to be done for other architectures.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-12-mathieu.desnoyers@efficios.com
This feature allows the scheduler to expose a per-memory map concurrency
ID to user-space. This concurrency ID is within the possible cpus range,
and is temporarily (and uniquely) assigned while threads are actively
running within a memory map. If a memory map has fewer threads than
cores, or is limited to run on few cores concurrently through sched
affinity or cgroup cpusets, the concurrency IDs will be values close
to 0, thus allowing efficient use of user-space memory for per-cpu
data structures.
This feature is meant to be exposed by a new rseq thread area field.
The primary purpose of this feature is to do the heavy-lifting needed
by memory allocators to allow them to use per-cpu data structures
efficiently in the following situations:
- Single-threaded applications,
- Multi-threaded applications on large systems (many cores) with limited
cpu affinity mask,
- Multi-threaded applications on large systems (many cores) with
restricted cgroup cpuset per container.
One of the key concern from scheduler maintainers is the overhead
associated with additional spin locks or atomic operations in the
scheduler fast-path. This is why the following optimization is
implemented.
On context switch between threads belonging to the same memory map,
transfer the mm_cid from prev to next without any atomic ops. This
takes care of use-cases involving frequent context switch between
threads belonging to the same memory map.
Additional optimizations can be done if the spin locks added when
context switching between threads belonging to different memory maps end
up being a performance bottleneck. Those are left out of this patch
though. A performance impact would have to be clearly demonstrated to
justify the added complexity.
The credit goes to Paul Turner (Google) for the original virtual cpu id
idea. This feature is implemented based on the discussions with Paul
Turner and Peter Oskolkov (Google), but I took the liberty to implement
scheduler fast-path optimizations and my own NUMA-awareness scheme. The
rumor has it that Google have been running a rseq vcpu_id extension
internally in production for a year. The tcmalloc source code indeed has
comments hinting at a vcpu_id prototype extension to the rseq system
call [1].
The following benchmarks do not show any significant overhead added to
the scheduler context switch by this feature:
* perf bench sched messaging (process)
Baseline: 86.5±0.3 ms
With mm_cid: 86.7±2.6 ms
* perf bench sched messaging (threaded)
Baseline: 84.3±3.0 ms
With mm_cid: 84.7±2.6 ms
* hackbench (process)
Baseline: 82.9±2.7 ms
With mm_cid: 82.9±2.9 ms
* hackbench (threaded)
Baseline: 85.2±2.6 ms
With mm_cid: 84.4±2.9 ms
[1] https://github.com/google/tcmalloc/blob/master/tcmalloc/internal/linux_syscall_support.h#L26
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-8-mathieu.desnoyers@efficios.com
Adding the NUMA node id to struct rseq is a straightforward thing to do,
and a good way to figure out if anything in the user-space ecosystem
prevents extending struct rseq.
This NUMA node id field allows memory allocators such as tcmalloc to
take advantage of fast access to the current NUMA node id to perform
NUMA-aware memory allocation.
It can also be useful for implementing fast-paths for NUMA-aware
user-space mutexes.
It also allows implementing getcpu(2) purely in user-space.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-5-mathieu.desnoyers@efficios.com
Introduce the extensible rseq ABI, where the feature size supported by
the kernel and the required alignment are communicated to user-space
through ELF auxiliary vectors.
This allows user-space to call rseq registration with a rseq_len of
either 32 bytes for the original struct rseq size (which includes
padding), or larger.
If rseq_len is larger than 32 bytes, then it must be large enough to
contain the feature size communicated to user-space through ELF
auxiliary vectors.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-4-mathieu.desnoyers@efficios.com
When linking the selftests against a libc which does not handle rseq
registration (before 2.35), rseq thread registration silently succeed
even with CONFIG_RSEQ=n because it erroneously thinks that libc is
handling rseq registration.
This is caused by setting the rseq ownership flag only after the
rseq_available() check. It should rather be set before the
rseq_available() check.
Set the rseq_size to 0 (error value) immediately after the
rseq_available() check fails rather than in the thread registration
functions.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-2-mathieu.desnoyers@efficios.com
CFS bandwidth currently distributes new runtime and unthrottles cfs_rq's
inline in an hrtimer callback. Runtime distribution is a per-cpu
operation, and unthrottling is a per-cgroup operation, since a tg walk
is required. On machines with a large number of cpus and large cgroup
hierarchies, this cpus*cgroups work can be too much to do in a single
hrtimer callback: since IRQ are disabled, hard lockups may easily occur.
Specifically, we've found this scalability issue on configurations with
256 cpus, O(1000) cgroups in the hierarchy being throttled, and high
memory bandwidth usage.
To fix this, we can instead unthrottle cfs_rq's asynchronously via a
CSD. Each cpu is responsible for unthrottling itself, thus sharding the
total work more fairly across the system, and avoiding hard lockups.
Signed-off-by: Josh Don <joshdon@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221117005418.3499691-1-joshdon@google.com
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown". After a timer is set to this state, then it can no
longer be re-armed.
The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed. It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.
This was created by using a coccinelle script and the following
commands:
$ cat timer.cocci
@@
expression ptr, slab;
identifier timer, rfield;
@@
(
- del_timer(&ptr->timer);
+ timer_shutdown(&ptr->timer);
|
- del_timer_sync(&ptr->timer);
+ timer_shutdown_sync(&ptr->timer);
)
... when strict
when != ptr->timer
(
kfree_rcu(ptr, rfield);
|
kmem_cache_free(slab, ptr);
|
kfree(ptr);
)
$ spatch timer.cocci . > /tmp/t.patch
$ patch -p1 < /tmp/t.patch
Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull spi fix from Mark Brown:
"One driver specific change here which handles the case where a SPI
device for some reason tries to change the bus speed during a message
on fsl_spi hardware, this should be very unusual"
* tag 'spi-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: fsl_spi: Don't change speed while chipselect is active
Pull regulator fixes from Mark Brown:
"Two core fixes here, one for a long standing race which some Qualcomm
systems have started triggering with their UFS driver and another
fixing a problem with supply lookup introduced by the fixes for devm
related use after free issues that were introduced in this merge
window"
* tag 'regulator-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: core: fix deadlock on regulator enable
regulator: core: Fix resolve supply lookup issue
Pull coccicheck update from Julia Lawall:
"Modernize use of grep in coccicheck:
Use 'grep -E' instead of 'egrep'"
* tag 'coccinelle-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
scripts: coccicheck: use "grep -E" instead of "egrep"
Pull kernel hardening fixes from Kees Cook:
- Fix CFI failure with KASAN (Sami Tolvanen)
- Fix LKDTM + CFI under GCC 7 and 8 (Kristina Martsenko)
- Limit CONFIG_ZERO_CALL_USED_REGS to Clang > 15.0.6 (Nathan
Chancellor)
- Ignore "contents" argument in LoadPin's LSM hook handling
- Fix paste-o in /sys/kernel/warn_count API docs
- Use READ_ONCE() consistently for oops/warn limit reading
* tag 'hardening-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
cfi: Fix CFI failure with KASAN
exit: Use READ_ONCE() for all oops/warn limit reads
security: Restrict CONFIG_ZERO_CALL_USED_REGS to gcc or clang > 15.0.6
lkdtm: cfi: Make PAC test work with GCC 7 and 8
docs: Fix path paste-o for /sys/kernel/warn_count
LoadPin: Ignore the "contents" argument of the LSM hooks
Pull dma-mapping fixes from Christoph Hellwig:
"Fix up the sound code to not pass __GFP_COMP to the non-coherent DMA
allocator, as it copes with that just as badly as the coherent
allocator, and then add a check to make sure no one passes the flag
ever again"
* tag 'dma-mapping-2022-12-23' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: reject GFP_COMP for noncoherent allocations
ALSA: memalloc: don't use GFP_COMP for non-coherent dma allocations
Pull 9p updates from Dominique Martinet:
- improve p9_check_errors to check buffer size instead of msize when
possible (e.g. not zero-copy)
- some more syzbot and KCSAN fixes
- minor headers include cleanup
* tag '9p-for-6.2-rc1' of https://github.com/martinetd/linux:
9p/client: fix data race on req->status
net/9p: fix response size check in p9_check_errors()
net/9p: distinguish zero-copy requests
9p/xen: do not memcpy header into req->rc
9p: set req refcount to zero to avoid uninitialized usage
9p/net: Remove unneeded idr.h #include
9p/fs: Remove unneeded idr.h #include
Pull more sound updates from Takashi Iwai:
"A few more updates for 6.2: most of changes are about ASoC
device-specific fixes.
- Lots of ASoC Intel AVS extensions and refactoring
- Quirks for ASoC Intel SOF as well as regression fixes
- ASoC Mediatek and Rockchip fixes
- Intel HD-audio HDMI workarounds
- Usual HD- and USB-audio device-specific quirks"
* tag 'sound-6.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (54 commits)
ALSA: usb-audio: Add new quirk FIXED_RATE for JBL Quantum810 Wireless
ALSA: azt3328: Remove the unused function snd_azf3328_codec_outl()
ASoC: lochnagar: Fix unused lochnagar_of_match warning
ASoC: Intel: Add HP Stream 8 to bytcr_rt5640.c
ASoC: SOF: mediatek: initialize panic_info to zero
ASoC: rt5670: Remove unbalanced pm_runtime_put()
ASoC: Intel: bytcr_rt5640: Add quirk for the Advantech MICA-071 tablet
ASoC: Intel: soc-acpi: update codec addr on 0C11/0C4F product
ASoC: rockchip: spdif: Add missing clk_disable_unprepare() in rk_spdif_runtime_resume()
ASoC: wm8994: Fix potential deadlock
ASoC: mediatek: mt8195: add sof be ops to check audio active
ASoC: SOF: Revert: "core: unregister clients and machine drivers in .shutdown"
ASoC: SOF: Intel: pci-tgl: unblock S5 entry if DMA stop has failed"
ALSA: hda/hdmi: fix stream-id config keep-alive for rt suspend
ALSA: hda/hdmi: set default audio parameters for KAE silent-stream
ALSA: hda/hdmi: fix i915 silent stream programming flow
ALSA: hda: Error out if invalid stream is being setup
ASoC: dt-bindings: fsl-sai: Reinstate i.MX93 SAI compatible string
ASoC: soc-pcm.c: Clear DAIs parameters after stream_active is updated
ASoC: codecs: wcd-clsh: Remove the unused function
...
Pull drm fixes from Dave Airlie:
"Holiday fixes!
Two batches from amd, and one group of i915 changes.
amdgpu:
- Spelling fix
- BO pin fix
- Properly handle polaris 10/11 overlap asics
- GMC9 fix
- SR-IOV suspend fix
- DCN 3.1.4 fix
- KFD userptr locking fix
- SMU13.x fixes
- GDS/GWS/OA handling fix
- Reserved VMID handling fixes
- FRU EEPROM fix
- BO validation fixes
- Avoid large variable on the stack
- S0ix fixes
- SMU 13.x fixes
- VCN fix
- Add missing fence reference
amdkfd:
- Fix init vm error handling
- Fix double release of compute pasid
i915
- Documentation fixes
- OA-perf related fix
- VLV/CHV HDMI/DP audio fix
- Display DDI/Transcoder fix
- Migrate fixes"
* tag 'drm-next-2022-12-23' of git://anongit.freedesktop.org/drm/drm: (39 commits)
drm/amdgpu: grab extra fence reference for drm_sched_job_add_dependency
drm/amdgpu: enable VCN DPG for GC IP v11.0.4
drm/amdgpu: skip mes self test after s0i3 resume for MES IP v11.0
drm/amd/pm: correct the fan speed retrieving in PWM for some SMU13 asics
drm/amd/pm: bump SMU13.0.0 driver_if header to version 0x34
drm/amdgpu: skip MES for S0ix as well since it's part of GFX
drm/amd/pm: avoid large variable on kernel stack
drm/amdkfd: Fix double release compute pasid
drm/amdkfd: Fix kfd_process_device_init_vm error handling
drm/amd/pm: update SMU13.0.0 reported maximum shader clock
drm/amd/pm: correct SMU13.0.0 pstate profiling clock settings
drm/amd/pm: enable GPO dynamic control support for SMU13.0.7
drm/amd/pm: enable GPO dynamic control support for SMU13.0.0
drm/amdgpu: revert "generally allow over-commit during BO allocation"
drm/amdgpu: Remove unnecessary domain argument
drm/amdgpu: Fix size validation for non-exclusive domains (v4)
drm/amdgpu: Check if fru_addr is not NULL (v2)
drm/i915/ttm: consider CCS for backup objects
drm/i915/migrate: fix corner case in CCS aux copying
drm/amdgpu: rework reserved VMID handling
...
Pull MIPS fixes from Thomas Bogendoerfer:
"Fixes due to DT changes"
* tag 'mips_6.2_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: dts: bcm63268: Add missing properties to the TWD node
MIPS: ralink: mt7621: avoid to init common ralink reset controller
Pull hotfixes from Andrew Morton:
"Eight fixes, all cc:stable. One is for gcov and the remainder are MM"
* tag 'mm-hotfixes-stable-2022-12-22-14-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
gcov: add support for checksum field
test_maple_tree: add test for mas_spanning_rebalance() on insufficient data
maple_tree: fix mas_spanning_rebalance() on insufficient data
hugetlb: really allocate vma lock for all sharable vmas
kmsan: export kmsan_handle_urb
kmsan: include linux/vmalloc.h
mm/mempolicy: fix memory leak in set_mempolicy_home_node system call
mm, mremap: fix mremap() expanding vma with addr inside vma
If mem-type is specified in the device tree
it would end up overriding the record_size
field instead of populating mem_type.
As record_size is currently parsed after the
improper assignment with default size 0 it
continued to work as expected regardless of the
value found in the device tree.
Simply changing the target field of the struct
is enough to get mem-type working as expected.
Fixes: 9d843e8faf ("pstore: Add mem_type property DT parsing support")
Cc: stable@vger.kernel.org
Signed-off-by: Luca Stefani <luca@osomprivacy.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221222131049.286288-1-luca@osomprivacy.com
When CFI_CLANG and KASAN are both enabled, LLVM doesn't generate a
CFI type hash for asan.module_ctor functions in translation units
where CFI is disabled, which leads to a CFI failure during boot when
do_ctors calls the affected constructors:
CFI failure at do_basic_setup+0x64/0x90 (target:
asan.module_ctor+0x0/0x28; expected type: 0xa540670c)
Specifically, this happens because CFI is disabled for
kernel/cfi.c. There's no reason to keep CFI disabled here anymore, so
fix the failure by not filtering out CC_FLAGS_CFI for the file.
Note that https://reviews.llvm.org/rG3b14862f0a96 fixed the issue
where LLVM didn't emit CFI type hashes for any sanitizer constructors,
but now type hashes are emitted correctly for TUs that use CFI.
Link: https://github.com/ClangBuiltLinux/linux/issues/1742
Fixes: 8924560094 ("cfi: Switch to -fsanitize=kcfi")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221222225747.3538676-1-samitolvanen@google.com
Pull more SCSI updates from James Bottomley:
"Mostly small bug fixes and small updates.
The only things of note is a qla2xxx fix for crash on hotplug and
timeout and the addition of a user exposed abstraction layer for
persistent reservation error return handling (which necessitates the
conversion of nvme.c as well as SCSI)"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: qla2xxx: Fix crash when I/O abort times out
nvme: Convert NVMe errors to PR errors
scsi: sd: Convert SCSI errors to PR errors
scsi: core: Rename status_byte to sg_status_byte
block: Add error codes for common PR failures
scsi: sd: sd_zbc: Trace zone append emulation
scsi: libfc: Include the correct header
