Commit Graph

756 Commits

Author SHA1 Message Date
Petr Mladek
335a42ebb0 workqueue: Fix hung time report of worker pools
The workqueue watchdog prints a warning when there is no progress in
a worker pool. Where the progress means that the pool started processing
a pending work item.

Note that it is perfectly fine to process work items much longer.
The progress should be guaranteed by waking up or creating idle
workers.

show_one_worker_pool() prints state of non-idle worker pool. It shows
a delay since the last pool->watchdog_ts.

The timestamp is updated when a first pending work is queued in
__queue_work(). Also it is updated when a work is dequeued for
processing in worker_thread() and rescuer_thread().

The delay is misleading when there is no pending work item. In this
case it shows how long the last work item is being proceed. Show
zero instead. There is no stall if there is no pending work.

Fixes: 82607adcf9 ("workqueue: implement lockup detector")
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-03-17 12:03:46 -10:00
Ammar Faizi
a8ec5880bd workqueue: Simplify a pr_warn() call in wq_select_unbound_cpu()
Use pr_warn_once() to achieve the same thing. It's simpler.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-03-17 11:49:03 -10:00
Valentin Schneider
c63a2e52d5 workqueue: Fold rebind_worker() within rebind_workers()
!CONFIG_SMP builds complain about rebind_worker() being unused. Its only
user, rebind_workers() is indeed only defined for CONFIG_SMP, so just fold
the two lines back up there.

Link: http://lore.kernel.org/r/20230113143102.2e94d74f@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-13 07:50:40 -10:00
Valentin Schneider
e02b931248 workqueue: Unbind kworkers before sending them to exit()
It has been reported that isolated CPUs can suffer from interference due to
per-CPU kworkers waking up just to die.

A surge of workqueue activity during initial setup of a latency-sensitive
application (refresh_vm_stats() being one of the culprits) can cause extra
per-CPU kworkers to be spawned. Then, said latency-sensitive task can be
running merrily on an isolated CPU only to be interrupted sometime later by
a kworker marked for death (cf. IDLE_WORKER_TIMEOUT, 5 minutes after last
kworker activity).

Prevent this by affining kworkers to the wq_unbound_cpumask (which doesn't
contain isolated CPUs, cf. HK_TYPE_WQ) before waking them up after marking
them with WORKER_DIE.

Changing the affinity does require a sleepable context, leverage the newly
introduced pool->idle_cull_work to get that.

Remove dying workers from pool->workers and keep track of them in a
separate list. This intentionally prevents for_each_loop_worker() from
iterating over workers that are marked for death.

Rename destroy_worker() to set_working_dying() to better reflect its
effects and relationship with wake_dying_workers().

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-12 06:21:49 -10:00
Valentin Schneider
9ab03be42b workqueue: Don't hold any lock while rcuwait'ing for !POOL_MANAGER_ACTIVE
put_unbound_pool() currently passes wq_manager_inactive() as exit condition
to rcuwait_wait_event(), which grabs pool->lock to check for

  pool->flags & POOL_MANAGER_ACTIVE

A later patch will require destroy_worker() to be invoked with
wq_pool_attach_mutex held, which needs to be acquired before
pool->lock. A mutex cannot be acquired within rcuwait_wait_event(), as
it could clobber the task state set by rcuwait_wait_event()

Instead, restructure the waiting logic to acquire any necessary lock
outside of rcuwait_wait_event().

Since further work cannot be inserted into unbound pwqs that have reached
->refcnt==0, this is bound to make forward progress as eventually the
worklist will be drained and need_more_worker(pool) will remain false,
preventing any worker from stealing the manager position from us.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-12 06:21:49 -10:00
Valentin Schneider
3f959aa3b3 workqueue: Convert the idle_timer to a timer + work_struct
A later patch will require a sleepable context in the idle worker timeout
function. Converting worker_pool.idle_timer to a delayed_work gives us just
that, however this would imply turning all idle_timer expiries into
scheduler events (waking up a worker to handle the dwork).

Instead, implement a "custom dwork" where the timer callback does some
extra checks before queuing the associated work.

No change in functionality intended.

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-12 06:21:49 -10:00
Valentin Schneider
793777bc19 workqueue: Factorize unbind/rebind_workers() logic
Later patches will reuse this code, move it into reusable functions.

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-12 06:21:49 -10:00
Lai Jiangshan
99c621ef24 workqueue: Protects wq_unbound_cpumask with wq_pool_attach_mutex
When unbind_workers() reads wq_unbound_cpumask to set the affinity of
freshly-unbound kworkers, it only holds wq_pool_attach_mutex. This isn't
sufficient as wq_unbound_cpumask is only protected by wq_pool_mutex.

Make wq_unbound_cpumask protected with wq_pool_attach_mutex and also
remove the need of temporary saved_cpumask.

Fixes: 10a5a651e3 ("workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs")
Reported-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-12 06:21:48 -10:00
Paul E. McKenney
c76feb0d5d workqueue: Make show_pwq() use run-length encoding
The show_pwq() function dumps out a pool_workqueue structure's activity,
including the pending work-queue handlers:

 Showing busy workqueues and worker pools:
 workqueue events: flags=0x0
   pwq 0: cpus=0 node=0 flags=0x1 nice=0 active=10/256 refcnt=11
     in-flight: 7:test_work_func, 64:test_work_func, 249:test_work_func
     pending: test_work_func, test_work_func, test_work_func1, test_work_func1, test_work_func1, test_work_func1, test_work_func1

When large systems are facing certain types of hang conditions, it is not
unusual for this "pending" list to contain runs of hundreds of identical
function names.  This "wall of text" is difficult to read, and worse yet,
it can be interleaved with other output such as stack traces.

Therefore, make show_pwq() use run-length encoding so that the above
printout instead looks like this:

 Showing busy workqueues and worker pools:
 workqueue events: flags=0x0
   pwq 0: cpus=0 node=0 flags=0x1 nice=0 active=10/256 refcnt=11
     in-flight: 7:test_work_func, 64:test_work_func, 249:test_work_func
     pending: 2*test_work_func, 5*test_work_func1

When no comma would be printed, including the WORK_STRUCT_LINKED case,
a new run is started unconditionally.

This output is more readable, places less stress on the hardware,
firmware, and software on the console-log path, and reduces interference
with other output.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-06 14:23:24 -10:00
Richard Clark
33e3f0a335 workqueue: Add a new flag to spot the potential UAF error
Currently if the user queues a new work item unintentionally
into a wq after the destroy_workqueue(wq), the work still can
be queued and scheduled without any noticeable kernel message
before the end of a RCU grace period.

As a debug-aid facility, this commit adds a new flag
__WQ_DESTROYING to spot that issue by triggering a kernel WARN
message.

Signed-off-by: Richard Clark <richard.xnu.clark@gmail.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-01-04 12:25:29 -10:00
Uladzislau Rezki
a7e30c0e9a workqueue: Make queue_rcu_work() use call_rcu_hurry()
Earlier commits in this series allow battery-powered systems to build
their kernels with the default-disabled CONFIG_RCU_LAZY=y Kconfig option.
This Kconfig option causes call_rcu() to delay its callbacks in order
to batch them.  This means that a given RCU grace period covers more
callbacks, thus reducing the number of grace periods, in turn reducing
the amount of energy consumed, which increases battery lifetime which
can be a very good thing.  This is not a subtle effect: In some important
use cases, the battery lifetime is increased by more than 10%.

This CONFIG_RCU_LAZY=y option is available only for CPUs that offload
callbacks, for example, CPUs mentioned in the rcu_nocbs kernel boot
parameter passed to kernels built with CONFIG_RCU_NOCB_CPU=y.

Delaying callbacks is normally not a problem because most callbacks do
nothing but free memory.  If the system is short on memory, a shrinker
will kick all currently queued lazy callbacks out of their laziness,
thus freeing their memory in short order.  Similarly, the rcu_barrier()
function, which blocks until all currently queued callbacks are invoked,
will also kick lazy callbacks, thus enabling rcu_barrier() to complete
in a timely manner.

However, there are some cases where laziness is not a good option.
For example, synchronize_rcu() invokes call_rcu(), and blocks until
the newly queued callback is invoked.  It would not be a good for
synchronize_rcu() to block for ten seconds, even on an idle system.
Therefore, synchronize_rcu() invokes call_rcu_hurry() instead of
call_rcu().  The arrival of a non-lazy call_rcu_hurry() callback on a
given CPU kicks any lazy callbacks that might be already queued on that
CPU.  After all, if there is going to be a grace period, all callbacks
might as well get full benefit from it.

Yes, this could be done the other way around by creating a
call_rcu_lazy(), but earlier experience with this approach and
feedback at the 2022 Linux Plumbers Conference shifted the approach
to call_rcu() being lazy with call_rcu_hurry() for the few places
where laziness is inappropriate.

And another call_rcu() instance that cannot be lazy is the one
in queue_rcu_work(), given that callers to queue_rcu_work() are
not necessarily OK with long delays.

Therefore, make queue_rcu_work() use call_rcu_hurry() in order to revert
to the old behavior.

[ paulmck: Apply s/call_rcu_flush/call_rcu_hurry/ feedback from Tejun Heo. ]

Signed-off-by: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-11-30 13:17:05 -08:00
Linus Torvalds
865dad2022 Merge tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull kcfi updates from Kees Cook:
 "This replaces the prior support for Clang's standard Control Flow
  Integrity (CFI) instrumentation, which has required a lot of special
  conditions (e.g. LTO) and work-arounds.

  The new implementation ("Kernel CFI") is specific to C, directly
  designed for the Linux kernel, and takes advantage of architectural
  features like x86's IBT. This series retains arm64 support and adds
  x86 support.

  GCC support is expected in the future[1], and additional "generic"
  architectural support is expected soon[2].

  Summary:

   - treewide: Remove old CFI support details

   - arm64: Replace Clang CFI support with Clang KCFI support

   - x86: Introduce Clang KCFI support"

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048 [1]
Link: https://github.com/samitolvanen/llvm-project/commits/kcfi_generic [2]

* tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
  x86: Add support for CONFIG_CFI_CLANG
  x86/purgatory: Disable CFI
  x86: Add types to indirectly called assembly functions
  x86/tools/relocs: Ignore __kcfi_typeid_ relocations
  kallsyms: Drop CONFIG_CFI_CLANG workarounds
  objtool: Disable CFI warnings
  objtool: Preserve special st_shndx indexes in elf_update_symbol
  treewide: Drop __cficanonical
  treewide: Drop WARN_ON_FUNCTION_MISMATCH
  treewide: Drop function_nocfi
  init: Drop __nocfi from __init
  arm64: Drop unneeded __nocfi attributes
  arm64: Add CFI error handling
  arm64: Add types to indirect called assembly functions
  psci: Fix the function type for psci_initcall_t
  lkdtm: Emit an indirect call for CFI tests
  cfi: Add type helper macros
  cfi: Switch to -fsanitize=kcfi
  cfi: Drop __CFI_ADDRESSABLE
  cfi: Remove CONFIG_CFI_CLANG_SHADOW
  ...
2022-10-03 17:11:07 -07:00
Sami Tolvanen
4b24356312 treewide: Drop WARN_ON_FUNCTION_MISMATCH
CONFIG_CFI_CLANG no longer breaks cross-module function address
equality, which makes WARN_ON_FUNCTION_MISMATCH unnecessary. Remove
the definition and switch back to WARN_ON_ONCE.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-15-samitolvanen@google.com
2022-09-26 10:13:14 -07:00
Tetsuo Handa
c0feea594e workqueue: don't skip lockdep work dependency in cancel_work_sync()
Like Hillf Danton mentioned

  syzbot should have been able to catch cancel_work_sync() in work context
  by checking lockdep_map in __flush_work() for both flush and cancel.

in [1], being unable to report an obvious deadlock scenario shown below is
broken. From locking dependency perspective, sync version of cancel request
should behave as if flush request, for it waits for completion of work if
that work has already started execution.

  ----------
  #include <linux/module.h>
  #include <linux/sched.h>
  static DEFINE_MUTEX(mutex);
  static void work_fn(struct work_struct *work)
  {
    schedule_timeout_uninterruptible(HZ / 5);
    mutex_lock(&mutex);
    mutex_unlock(&mutex);
  }
  static DECLARE_WORK(work, work_fn);
  static int __init test_init(void)
  {
    schedule_work(&work);
    schedule_timeout_uninterruptible(HZ / 10);
    mutex_lock(&mutex);
    cancel_work_sync(&work);
    mutex_unlock(&mutex);
    return -EINVAL;
  }
  module_init(test_init);
  MODULE_LICENSE("GPL");
  ----------

The check this patch restores was added by commit 0976dfc1d0
("workqueue: Catch more locking problems with flush_work()").

Then, lockdep's crossrelease feature was added by commit b09be676e0
("locking/lockdep: Implement the 'crossrelease' feature"). As a result,
this check was once removed by commit fd1a5b04df ("workqueue: Remove
now redundant lock acquisitions wrt. workqueue flushes").

But lockdep's crossrelease feature was removed by commit e966eaeeb6
("locking/lockdep: Remove the cross-release locking checks"). At this
point, this check should have been restored.

Then, commit d6e89786be ("workqueue: skip lockdep wq dependency in
cancel_work_sync()") introduced a boolean flag in order to distinguish
flush_work() and cancel_work_sync(), for checking "struct workqueue_struct"
dependency when called from cancel_work_sync() was causing false positives.

Then, commit 87915adc3f ("workqueue: re-add lockdep dependencies for
flushing") tried to restore "struct work_struct" dependency check, but by
error checked this boolean flag. Like an example shown above indicates,
"struct work_struct" dependency needs to be checked for both flush_work()
and cancel_work_sync().

Link: https://lkml.kernel.org/r/20220504044800.4966-1-hdanton@sina.com [1]
Reported-by: Hillf Danton <hdanton@sina.com>
Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com>
Fixes: 87915adc3f ("workqueue: re-add lockdep dependencies for flushing")
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-08-16 06:27:35 -10:00
Linus Torvalds
b44f2fd879 Merge tag 'drm-next-2022-08-03' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie:
 "Highlights:

   - New driver for logicvc - which is a display IP core.

   - EDID parser rework to add new extensions

   - fbcon scrolling improvements

   - i915 has some more DG2 work but not enabled by default, but should
     have enough features for userspace to work now.

  Otherwise it's lots of work all over the place. Detailed summary:

  New driver:
   - logicvc

  vfio:
   - use aperture API

  core:
   - of: Add data-lane helpers and convert drivers
   - connector: Remove deprecated ida_simple_get()

  media:
   - Add various RGB666 and RGB888 format constants

  panel:
   - Add HannStar HSD101PWW
   - Add ETML0700Y5DHA

  dma-buf:
   - add sync-file API
   - set dma mask for udmabuf devices

  fbcon:
   - Improve scrolling performance
   - Sanitize input

  fbdev:
   - device unregistering fixes
   - vesa: Support COMPILE_TEST
   - Disable firmware-device registration when first native driver loads

  aperture:
   - fix segfault during hot-unplug
   - export for use with other subsystems

  client:
   - use driver validated modes

  dp:
   - aux: make probing more reliable
   - mst: Read extended DPCD capabilities during system resume
   - Support waiting for HDP signal
   - Port-validation fixes

  edid:
   - CEA data-block iterators
   - struct drm_edid introduction
   - implement HF-EEODB extension

  gem:
   - don't use fb format non-existing planes

  probe-helper:
   - use 640x480 as displayport fallback

  scheduler:
   - don't kill jobs in interrupt context

  bridge:
   - Add support for i.MX8qxp and i.MX8qm
   - lots of fixes/cleanups
   - Add TI-DLPC3433
   - fy07024di26a30d: Optional GPIO reset
   - ldb: Add reg and reg-name properties to bindings, Kconfig fixes
   - lt9611: Fix display sensing;
   - tc358767: DSI/DPI refactoring and DSI-to-eDP support, DSI lane handling
   - tc358775: Fix clock settings
   - ti-sn65dsi83: Allow GPIO to sleep
   - adv7511: I2C fixes
   - anx7625: Fix error handling; DPI fixes; Implement HDP timeout via callback
   - fsl-ldb: Drop DE flip
   - ti-sn65dsi86: Convert to atomic modesetting

  amdgpu:
   - use atomic fence helpers in DM
   - fix VRAM address calculations
   - export CRTC bpc via debugfs
   - Initial devcoredump support
   - Enable high priority gfx queue on asics which support it
   - Adjust GART size on newer APUs for S/G display
   - Soft reset for GFX 11 / SDMA 6
   - Add gfxoff status query for vangogh
   - Fix timestamps for cursor only commits
   - Adjust GART size on newer APUs for S/G display
   - fix buddy memory corruption

  amdkfd:
   - MMU notifier fixes
   - P2P DMA support using dma-buf
   - Add available memory IOCTL
   - HMM profiler support
   - Simplify GPUVM validation
   - Unified memory for CWSR save/restore area

  i915:
   - General driver clean-up
   - DG2 enabling (still under force probe)
       - DG2 small BAR memory support
       - HuC loading support
       - DG2 workarounds
       - DG2/ATS-M device IDs added
   - Ponte Vecchio prep work and new blitter engines
   - add Meteorlake support
   - Fix sparse warnings
   - DMC MMIO range checks
   - Audio related fixes
   - Runtime PM fixes
   - PSR fixes
   - Media freq factor and per-gt enhancements
   - DSI fixes for ICL+
   - Disable DMC flip queue handlers
   - ADL_P voltage swing updates
   - Use more the VBT for panel information
   - Fix on Type-C ports with TBT mode
   - Improve fastset and allow seamless M/N changes
   - Accept more fixed modes with VRR/DMRRS panels
   - Disable connector polling for a headless SKU
   - ADL-S display PLL w/a
   - Enable THP on Icelake and beyond
   - Fix i915_gem_object_ggtt_pin_ww regression on old platforms
   - Expose per tile media freq factor in sysfs
   - Fix dma_resv fence handling in multi-batch execbuf
   - Improve on suspend / resume time with VT-d enabled
   - export CRTC bpc settings via debugfs

  msm:
   - gpu: a619 support
   - gpu: Fix for unclocked GMU register access
   - gpu: Devcore dump enhancements
   - client utilization via fdinfo support
   - fix fence rollover issue
   - gem: Lockdep false-positive warning fix
   - gem: Switch to pfn mappings
   - WB support on sc7180
   - dp: dropped custom bulk clock implementation
   - fix link retraining on resolution change
   - hdmi: dropped obsolete GPIO support

  tegra:
   - context isolation for host1x engines
   - tegra234 soc support

  mediatek:
   - add vdosys0/1 for mt8195
   - add MT8195 dp_intf driver

  exynos:
   - Fix resume function issue of exynos decon driver by calling
     clk_disable_unprepare() properly if clk_prepare_enable() failed.

  nouveau:
   - set of misc fixes/cleanups
   - display cleanups

  gma500:
   - Cleanup connector I2C handling

  hyperv:
   - Unify VRAM allocation of Gen1 and Gen2

  meson:
   - Support YUV422 output; Refcount fixes

  mgag200:
   - Support damage clipping
   - Support gamma handling
   - Protect concurrent HW access
   - Fixes to connector
   - Store model-specific limits in device-info structure
   - fix PCI register init

  panfrost:
   - Valhall support

  r128:
   - Fix bit-shift overflow

  rockchip:
   - Locking fixes in error path

  ssd130x:
   - Fix built-in linkage

  udl:
   - Always advertize VGA connector

  ast:
   - Support multiple outputs
   - fix black screen on resume

  sun4i:
   - HDMI PHY cleanups

  vc4:
   - Add support for BCM2711

  vkms:
   - Allocate output buffer with vmalloc()

  mcde:
   - Fix ref-count leak

  mxsfb/lcdif:
   - Support i.MX8MP LCD controller

  stm/ltdc:
   - Support dynamic Z order
   - Support mirroring

  ingenic:
   - Fix display at maximum resolution"

* tag 'drm-next-2022-08-03' of git://anongit.freedesktop.org/drm/drm: (1480 commits)
  drm/amd/display: Fix a compilation failure on PowerPC caused by FPU code
  drm/amdgpu: enable support for psp 13.0.4 block
  drm/amdgpu: add files for PSP 13.0.4
  drm/amdgpu: add header files for MP 13.0.4
  drm/amdgpu: correct RLC_RLCS_BOOTLOAD_STATUS offset and index
  drm/amdgpu: send msg to IMU for the front-door loading
  drm/amdkfd: use time_is_before_jiffies(a + b) to replace "jiffies - a > b"
  drm/amdgpu: fix hive reference leak when reflecting psp topology info
  drm/amd/pm: enable GFX ULV feature support for SMU13.0.0
  drm/amd/pm: update driver if header for SMU 13.0.0
  drm/amdgpu: move mes self test after drm sched re-started
  drm/amdgpu: drop non-necessary call trace dump
  drm/amdgpu: enable VCN cg and JPEG cg/pg
  drm/amdgpu: vcn_4_0_2 video codec query
  drm/amdgpu: add VCN_4_0_2 firmware support
  drm/amdgpu: add VCN function in NBIO v7.7
  drm/amdgpu: fix a vcn4 boot poll bug in emulation mode
  drm/amd/amdgpu: add memory training support for PSP_V13
  drm/amdkfd: remove an unnecessary amdgpu_bo_ref
  drm/amd/pm: Add get_gfx_off_status interface for yellow carp
  ...
2022-08-03 19:52:08 -07:00
Lai Jiangshan
46a4d679ef workqueue: Avoid a false warning in unbind_workers()
Doing set_cpus_allowed_ptr() with wq_unbound_cpumask can be possible
fails and trigger the false warning.

Use cpu_possible_mask instead when wq_unbound_cpumask has no active CPUs.

It is very easy to trigger the warning:
  Set wq_unbound_cpumask to a small set of CPUs.
  Offline all the CPUs of wq_unbound_cpumask.
  Offline an extra CPU and trigger the warning.

Fixes: 10a5a651e3 ("workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs")
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-07-29 07:49:02 -10:00
Dave Airlie
344feb7ccf Merge tag 'amd-drm-next-5.20-2022-07-05' of https://gitlab.freedesktop.org/agd5f/linux into drm-next
amd-drm-next-5.20-2022-07-05:

amdgpu:
- Various spelling and grammer fixes
- Various eDP fixes
- Various DMCUB fixes
- VCN fixes
- GMC 11 fixes
- RAS fixes
- TMZ support for GC 10.3.7
- GPUVM TLB flush fixes
- SMU 13.0.x updates
- DCN 3.2 Support
- DCN 3.2.1 Support
- MES updates
- GFX11 modifiers support
- USB-C fixes
- MMHUB 3.0.1 support
- SDMA 6.0 doorbell fixes
- Initial devcoredump support
- Enable high priority gfx queue on asics which support it
- Enable GPU reset for SMU 13.0.4
- OLED display fixes
- MPO fixes
- DC frame size fixes
- ASPM support for PCIE 7.4/7.6
- GPU reset support for SMU 13.0.0
- GFX11 updates
- VCN JPEG fix
- BACO support for SMU 13.0.7
- VCN instance handling fix
- GFX8 GPUVM TLB flush fix
- GPU reset rework
- VCN 4.0.2 support
- GTT size fixes
- DP link training fixes
- LSDMA 6.0.1 support
- Various backlight fixes
- Color encoding fixes
- Backlight config cleanup
- VCN 4.x unified queue cleanup

amdkfd:
- MMU notifier fixes
- Updates for GC 10.3.6 and 10.3.7
- P2P DMA support using dma-buf
- Add available memory IOCTL
- SDMA 6.0.1 fix
- MES fixes
- HMM profiler support

radeon:
- License fix
- Backlight config cleanup

UAPI:
- Add available memory IOCTL to amdkfd
  Proposed userspace: https://www.mail-archive.com/amd-gfx@lists.freedesktop.org/msg75743.html
- HMM profiler support for amdkfd
  Proposed userspace: https://lists.freedesktop.org/archives/amd-gfx/2022-June/080805.html

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220705212633.6037-1-alexander.deucher@amd.com
2022-07-12 11:07:32 +10:00
Andrey Grodzovsky
73b4b53276 Revert "workqueue: remove unused cancel_work()"
This reverts commit 6417250d3f.

amdpgu need this function in order to prematurly stop pending
reset works when another reset work already in progress.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Lai Jiangshan<jiangshanlai@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2022-06-10 15:24:38 -04:00
Tetsuo Handa
c4f135d643 workqueue: Wrap flush_workqueue() using a macro
Since flush operation synchronously waits for completion, flushing
system-wide WQs (e.g. system_wq) might introduce possibility of deadlock
due to unexpected locking dependency. Tejun Heo commented at [1] that it
makes no sense at all to call flush_workqueue() on the shared WQs as the
caller has no idea what it's gonna end up waiting for.

Although there is flush_scheduled_work() which flushes system_wq WQ with
"Think twice before calling this function! It's very easy to get into
trouble if you don't take great care." warning message, syzbot found a
circular locking dependency caused by flushing system_wq WQ [2].

Therefore, let's change the direction to that developers had better use
their local WQs if flush_scheduled_work()/flush_workqueue(system_*_wq) is
inevitable.

Steps for converting system-wide WQs into local WQs are explained at [3],
and a conversion to stop flushing system-wide WQs is in progress. Now we
want some mechanism for preventing developers who are not aware of this
conversion from again start flushing system-wide WQs.

Since I found that WARN_ON() is complete but awkward approach for teaching
developers about this problem, let's use __compiletime_warning() for
incomplete but handy approach. For completeness, we will also insert
WARN_ON() into __flush_workqueue() after all in-tree users stopped calling
flush_scheduled_work().

Link: https://lore.kernel.org/all/YgnQGZWT%2Fn3VAITX@slm.duckdns.org/ [1]
Link: https://syzkaller.appspot.com/bug?extid=bde0f89deacca7c765b8 [2]
Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp [3]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-06-07 07:07:14 -10:00
Zqiang
10a5a651e3 workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs
When a CPU is going offline, all workers on the CPU's pool will have their
cpus_allowed cleared to cpu_possible_mask and can run on any CPUs including
the isolated ones. Instead, set cpus_allowed to wq_unbound_cpumask so that
the can avoid isolated CPUs.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-04-21 12:31:04 -10:00
Linus Torvalds
7838316260 Merge branch 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "Nothing major. Just follow-up cleanups from Lai after the earlier
  synchronization simplification"

* 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Convert the type of pool->nr_running to int
  workqueue: Use wake_up_worker() in wq_worker_sleeping() instead of open code
  workqueue: Change the comments of the synchronization about the idle_list
  workqueue: Remove the mb() pair between wq_worker_sleeping() and insert_work()
2022-03-23 12:40:51 -07:00
Frederic Weisbecker
04d4e665a6 sched/isolation: Use single feature type while referring to housekeeping cpumask
Refer to housekeeping APIs using single feature types instead of flags.
This prevents from passing multiple isolation features at once to
housekeeping interfaces, which soon won't be possible anymore as each
isolation features will have their own cpumask.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
2022-02-16 15:57:55 +01:00
Frederic Weisbecker
7b45b51e77 workqueue: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetch
To prepare for supporting each feature of the housekeeping cpumask
toward cpuset, prepare each of the HK_FLAG_* entries to move to their
own cpumask with enforcing to fetch them individually. The new
constraint is that multiple HK_FLAG_* entries can't be mixed together
anymore in a single call to housekeeping cpumask().

This will later allow, for example, to runtime modify the cpulist passed
through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot
parameters.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220207155910.527133-3-frederic@kernel.org
2022-02-16 15:57:54 +01:00
Lai Jiangshan
bc35f7ef96 workqueue: Convert the type of pool->nr_running to int
It is only modified in associated CPU, so it doesn't need to be atomic.

tj: Comment updated.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-12 07:46:36 -10:00
Lai Jiangshan
cc5bff3846 workqueue: Use wake_up_worker() in wq_worker_sleeping() instead of open code
The wakeup code in wq_worker_sleeping() is the same as wake_up_worker().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-12 07:40:32 -10:00