A patchset worked out together with Peter Zijlstra. Ingo is OK with taking
it through the DRM tree:
This is a small fallout from a work to allow batching WW mutex locks and
unlocks.
Our Wound-Wait mutexes actually don't use the Wound-Wait algorithm but
the Wait-Die algorithm. One could perhaps rename those mutexes tree-wide to
"Wait-Die mutexes" or "Deadlock Avoidance mutexes". Another approach suggested
here is to implement also the "Wound-Wait" algorithm as a per-WW-class
choice, as it has advantages in some cases. See for example
http://www.mathcs.emory.edu/~cheung/Courses/554/Syllabus/8-recv+serial/deadlock-compare.html
Now Wound-Wait is a preemptive algorithm, and the preemption is implemented
using a lazy scheme: If a wounded transaction is about to go to sleep on
a contended WW mutex, we return -EDEADLK. That is sufficient for deadlock
prevention. Since with WW mutexes we also require the aborted transaction to
sleep waiting to lock the WW mutex it was aborted on, this choice also provides
a suitable WW mutex to sleep on. If we were to return -EDEADLK on the first
WW mutex lock after the transaction was wounded whether the WW mutex was
contended or not, the transaction might frequently be restarted without a wait,
which is far from optimal. Note also that with the lazy preemption scheme,
contrary to Wait-Die there will be no rollbacks on lock contention of locks
held by a transaction that has completed its locking sequence.
The modeset locks are then changed from Wait-Die to Wound-Wait since the
typical locking pattern of those locks very well matches the criterion for
a substantial reduction in the number of rollbacks. For reservation objects,
the benefit is more unclear at this point and they remain using Wait-Die.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180703105339.4461-1-thellstrom@vmware.com
Two requests have come in for a backmerge,
and I've got some pull reqs on rc2, so this
just makes sense.
Signed-off-by: Dave Airlie <airlied@redhat.com>
The current Wound-Wait mutex algorithm is actually not Wound-Wait but
Wait-Die. Implement also Wound-Wait as a per-ww-class choice. Wound-Wait
is, contrary to Wait-Die a preemptive algorithm and is known to generate
fewer backoffs. Testing reveals that this is true if the
number of simultaneous contending transactions is small.
As the number of simultaneous contending threads increases, Wait-Wound
becomes inferior to Wait-Die in terms of elapsed time.
Possibly due to the larger number of held locks of sleeping transactions.
Update documentation and callers.
Timings using git://people.freedesktop.org/~thomash/ww_mutex_test
tag patch-18-06-15
Each thread runs 100000 batches of lock / unlock 800 ww mutexes randomly
chosen out of 100000. Four core Intel x86_64:
Algorithm #threads Rollbacks time
Wound-Wait 4 ~100 ~17s.
Wait-Die 4 ~150000 ~19s.
Wound-Wait 16 ~360000 ~109s.
Wait-Die 16 ~450000 ~82s.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Co-authored-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
In commits:
34a2ab5e06 ("drm: Add acquire ctx parameter to ->update_plane")
1931529448 ("drm: Add acquire ctx parameter to ->plane_disable")
a pointer to a drm_modeset_acquire_ctx structure was added as an
argument to the method prototypes. The transitional helpers are
supposed to be directly plugged in as implementations of these
methods, but doing so generates a warning. Add the missing
argument.
A number of buggy users were added for drm_plane_helper_disable()
which need to be fixed up for this change, which we do by passing
a NULL ctx argument.
Fixes: 1931529448 ("drm: Add acquire ctx parameter to ->plane_disable")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/E1fa1Zr-0005gT-VF@rmk-PC.armlinux.org.uk
When this was introduced in
commit a519435a96
Author: Christian König <christian.koenig@amd.com>
Date: Tue Oct 20 16:34:16 2015 +0200
dma-buf/fence: add fence_wait_any_timeout function v2
there was a restriction added that this only works if the dma-fence
uses the dma_fence_default_wait hook. Which works for amdgpu, which is
the only caller. Well, until you share some buffers with e.g. i915,
then you get an -EINVAL.
But there's really no reason for this, because all drivers must
support callbacks. The special ->wait hook is only as an optimization;
if the driver needs to create a worker thread for an active callback,
then it can avoid to do that if it knows that there's a process
context available already. So ->wait is just an optimization, just
using the logic in dma_fence_default_wait() should work for all
drivers.
Let's remove this restriction.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180503142603.28513-4-daniel.vetter@ffwll.ch
Pull btrfs fixes from David Sterba:
"We have a few regression fixes for qgroup rescan status tracking and
the vm_fault_t conversion that mixed up the error values"
* tag 'for-4.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix mount failure when qgroup rescan is in progress
Btrfs: fix regression in btrfs_page_mkwrite() from vm_fault_t conversion
btrfs: quota: Set rescan progress to (u64)-1 if we hit last leaf
The Nomadik has a variant of the PL110 known as "Color LCD
Controller" LCDC. This variant has the same bit ordering as
the DRM subsystem (in difference from the other variants)
and adds a few bits for the control of 5551, 565 etc in the
control register. Notably it also adds a packed RGB888
24BPP mode.
We add support by detecting this variant and also adding a
small plug-in that will mux the LCDC out if the ASIC happens
to be muxed to the other graphics controller (they are
mutually exclusive).
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180621184450.25377-1-linus.walleij@linaro.org
Pull vfs fix from Al Viro:
"Followup to procfs-seq_file series this window"
This fixes a memory leak by making sure that proc seq files release any
private data on close. The 'proc_seq_open' has to be properly paired
with 'proc_seq_release' that releases the extra private data.
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
proc: add proc_seq_release
Pull staging/IIO fixes from Greg KH:
"Here are a few small staging and IIO driver fixes for 4.18-rc3.
Nothing major or big, all just fixes for reported problems since
4.18-rc1. All of these have been in linux-next this week with no
reported problems"
* tag 'staging-4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: android: ion: Return an ERR_PTR in ion_map_kernel
staging: comedi: quatech_daqp_cs: fix no-op loop daqp_ao_insn_write()
iio: imu: inv_mpu6050: Fix probe() failure on older ACPI based machines
iio: buffer: fix the function signature to match implementation
iio: mma8452: Fix ignoring MMA8452_INT_DRDY
iio: tsl2x7x/tsl2772: avoid potential division by zero
iio: pressure: bmp280: fix relative humidity unit
Pull tty/serial fixes from Greg KH:
"Here are five fixes for the tty core and some serial drivers.
The tty core ones fix some security and other issues reported by the
syzbot that I have taken too long in responding to (sorry Tetsuo!).
The 8350 serial driver fix resolves an issue of devices that used to
work properly stopping working as they shouldn't have been added to a
blacklist.
All of these have been in linux-next for a few days with no reported
issues"
* tag 'tty-4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
vt: prevent leaking uninitialized data to userspace via /dev/vcs*
serdev: fix memleak on module unload
serial: 8250_pci: Remove stalled entries in blacklist
n_tty: Access echo_* variables carefully.
n_tty: Fix stall at n_tty_receive_char_special().
Pull USB fixes from Greg KH:
"Here is a number of USB gadget and other driver fixes for 4.18-rc3.
There's a bunch of them here, most of them being gadget driver and
xhci host controller fixes for reported issues (as normal), but there
are also some new device ids, and some fixes for the typec code.
There is an acpi core patch in here that was acked by the acpi
maintainer as it is needed for the typec fixes in order to properly
solve a problem in that driver.
All of these have been in linux-next this week with no reported
issues"
* tag 'usb-4.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
usb: chipidea: host: fix disconnection detect issue
usb: typec: tcpm: fix logbuffer index is wrong if _tcpm_log is re-entered
typec: tcpm: Fix a msecs vs jiffies bug
NFC: pn533: Fix wrong GFP flag usage
usb: cdc_acm: Add quirk for Uniden UBC125 scanner
staging/typec: fix tcpci_rt1711h build errors
usb: typec: ucsi: Fix for incorrect status data issue
usb: typec: ucsi: acpi: Workaround for cache mode issue
acpi: Add helper for deactivating memory region
usb: xhci: increase CRS timeout value
usb: xhci: tegra: fix runtime PM error handling
usb: xhci: remove the code build warning
xhci: Fix kernel oops in trace_xhci_free_virt_device
xhci: Fix perceived dead host due to runtime suspend race with event handler
dwc2: gadget: Fix ISOC IN DDMA PID bitfield value calculation
usb: gadget: dwc2: fix memory leak in gadget_init()
usb: gadget: composite: fix delayed_status race condition when set_interface
usb: dwc2: fix isoc split in transfer with no data
usb: dwc2: alloc dma aligned buffer for isoc split in
usb: dwc2: fix the incorrect bitmaps for the ports of multi_tt hub
...
Pull dma mapping fixlet from Christoph Hellwig:
"Add a missing export required by riscv and unicore"
* tag 'dma-mapping-4.18-2' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: export swiotlb_dma_ops
Pull parisc fixes and cleanups from Helge Deller:
"Nothing exiting in this patchset, just
- small cleanups of header files
- default to 4 CPUs when building a SMP kernel
- mark 16kB and 64kB page sizes broken
- addition of the new io_pgetevents syscall"
* 'parisc-4.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Build kernel without -ffunction-sections
parisc: Reduce debug output in unwind code
parisc: Wire up io_pgetevents syscall
parisc: Default to 4 SMP CPUs
parisc: Convert printk(KERN_LEVEL) to pr_lvl()
parisc: Mark 16kB and 64kB page sizes BROKEN
parisc: Drop struct sigaction from not exported header file
Pull ARM SoC fixes from Olof Johansson:
"A smaller batch for the end of the week (let's see if I can keep the
weekly cadence going for once).
All medium-grade fixes here, nothing worrisome:
- Fixes for some fairly old bugs around SD card write-protect
detection and GPIO interrupt assignments on Davinci.
- Wifi module suspend fix for Hikey.
- Minor DT tweaks to fix inaccuracies for Amlogic platforms, one
of which solves booting with third-party u-boot"
* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
arm64: dts: hikey960: Define wl1837 power capabilities
arm64: dts: hikey: Define wl1835 power capabilities
ARM64: dts: meson-gxl: fix Mali GPU compatible string
ARM64: dts: meson-axg: fix ethernet stability issue
ARM64: dts: meson-gx: fix ATF reserved memory region
ARM64: dts: meson-gxl-s905x-p212: Add phy-supply for usb0
ARM64: dts: meson: fix register ranges for SD/eMMC
ARM64: dts: meson: disable sd-uhs modes on the libretech-cc
ARM: dts: da850: Fix interrups property for gpio
ARM: davinci: board-da850-evm: fix WP pin polarity for MMC/SD
Pull Kbuild fixes from Masahiro Yamada:
- introduce __diag_* macros and suppress -Wattribute-alias warnings
from GCC 8
- fix stack protector test script for x86_64
- fix line number handling in Kconfig
- document that '#' starts a comment in Kconfig
- handle P_SYMBOL property in dump debugging of Kconfig
- correct help message of LD_DEAD_CODE_DATA_ELIMINATION
- fix occasional segmentation faults in Kconfig
* tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: loop boundary condition fix
kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION
kconfig: handle P_SYMBOL in print_symbol()
kconfig: document Kconfig source file comments
kconfig: fix line numbers for if-entries in menu tree
stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y
powerpc: Remove -Wattribute-alias pragmas
disable -Wattribute-alias warning for SYSCALL_DEFINEx()
kbuild: add macro for controlling warnings to linux/compiler.h
Pull x86 fixes from Ingo Molnar:
"The biggest diffstat comes from self-test updates, plus there's entry
code fixes, 5-level paging related fixes, console debug output fixes,
and misc fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Clean up the printk()s in show_fault_oops()
x86/mm: Drop unneeded __always_inline for p4d page table helpers
x86/efi: Fix efi_call_phys_epilog() with CONFIG_X86_5LEVEL=y
selftests/x86/sigreturn: Do minor cleanups
selftests/x86/sigreturn/64: Fix spurious failures on AMD CPUs
x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80"
x86/mm: Don't free P4D table when it is folded at runtime
x86/entry/32: Add explicit 'l' instruction suffix
x86/mm: Get rid of KERN_CONT in show_fault_oops()
Pull perf fixes from Ingo Molnar:
"Tooling fixes mostly, plus a build warning fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
perf/core: Move inline keyword at the beginning of declaration
tools/headers: Pick up latest kernel ABIs
perf tools: Fix crash caused by accessing feat_ops[HEADER_LAST_FEATURE]
perf script: Fix crash because of missing evsel->priv
perf script: Add missing output fields in a hint
perf bench: Fix numa report output code
perf stat: Remove duplicate event counting
perf alias: Rebuild alias expression string to make it comparable
perf alias: Remove trailing newline when reading sysfs files
perf tools: Fix a clang 7.0 compilation error
tools include uapi: Synchronize bpf.h with the kernel
tools include uapi: Update if_link.h to pick IFLA_{BRPORT_ISOLATED,VXLAN_TTL_INHERIT}
tools include powerpc: Update arch/powerpc/include/uapi/asm/unistd.h copy to get 'rseq' syscall
perf tools: Update x86's syscall_64.tbl, adding 'io_pgetevents' and 'rseq'
tools headers uapi: Synchronize drm/drm.h
perf intel-pt: Fix packet decoding of CYC packets
perf tests: Add valid callback for parse-events test
perf tests: Add event parsing error handling to parse events test
perf report powerpc: Fix crash if callchain is empty
perf test session topology: Fix test on s390
...
Pull selinux fix from Paul Moore:
"One fairly straightforward patch to fix a longstanding issue where a
process could stall while accessing files in selinuxfs and block
everyone else due to a held mutex.
The patch passes all our tests and looks to apply cleanly to your
current tree"
* tag 'selinux-pr-20180629' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: move user accesses in selinuxfs out of locked regions
Pull block fixes from Jens Axboe:
"Small set of fixes for this series. Mostly just minor fixes, the only
oddball in here is the sg change.
The sg change came out of the stall fix for NVMe, where we added a
mempool and limited us to a single page allocation. CONFIG_SG_DEBUG
sort-of ruins that, since we'd need to account for that. That's
actually a generic problem, since lots of drivers need to allocate SG
lists. So this just removes support for CONFIG_SG_DEBUG, which I added
back in 2007 and to my knowledge it was never useful.
Anyway, outside of that, this pull contains:
- clone of request with special payload fix (Bart)
- drbd discard handling fix (Bart)
- SATA blk-mq stall fix (me)
- chunk size fix (Keith)
- double free nvme rdma fix (Sagi)"
* tag 'for-linus-20180629' of git://git.kernel.dk/linux-block:
sg: remove ->sg_magic member
drbd: Fix drbd_request_prepare() discard handling
blk-mq: don't queue more if we get a busy return
block: Fix cloning of requests with a special payload
nvme-rdma: fix possible double free of controller async event buffer
block: Fix transfer when chunk sectors exceeds max
Pull powerpc fixes from Michael Ellerman:
"Two regression fixes, and a new syscall wire-up:
- A fix for the recent conversion to time64_t in the powermac RTC
routines, which caused time to go backward.
- Another fix for fallout from the split PMD PTL conversion.
- Wire up the new io_pgetevents() syscall.
Thanks to: Aneesh Kumar K.V, Arnd Bergmann, Breno Leitao, Mathieu
Malaterre"
* tag 'powerpc-4.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/powermac: Fix rtc read/write functions
powerpc/mm/32: Fix pgtable_page_dtor call
powerpc: Wire up io_pgetevents
This fixes polarity of SD card write-protect pin on DA850 EVM
and fixes interrupt property for DA850 SoC GPIO as defined in
device-tree.
Both of these are not introduced with v4.18 merge but have
existed prior.
* tag 'davinci-fixes-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nsekhar/linux-davinci:
ARM: dts: da850: Fix interrups property for gpio
ARM: davinci: board-da850-evm: fix WP pin polarity for MMC/SD
Signed-off-by: Olof Johansson <olof@lixom.net>
