1. 24 9月, 2021 7 次提交
  2. 23 9月, 2021 2 次提交
  3. 22 9月, 2021 7 次提交
  4. 21 9月, 2021 7 次提交
  5. 20 9月, 2021 3 次提交
  6. 19 9月, 2021 4 次提交
  7. 17 9月, 2021 1 次提交
    • M
      kernel/locking: Add context to ww_mutex_trylock() · 12235da8
      Maarten Lankhorst 提交于
      i915 will soon gain an eviction path that trylock a whole lot of locks
      for eviction, getting dmesg failures like below:
      
        BUG: MAX_LOCK_DEPTH too low!
        turning off the locking correctness validator.
        depth: 48  max: 48!
        48 locks held by i915_selftest/5776:
         #0: ffff888101a79240 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x88/0x160
         #1: ffffc900009778c0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.63+0x39/0x1b0 [i915]
         #2: ffff88800cf74de8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.63+0x5f/0x1b0 [i915]
         #3: ffff88810c7f9e38 (&vm->mutex/1){+.+.}-{3:3}, at: i915_vma_pin_ww+0x1c4/0x9d0 [i915]
         #4: ffff88810bad5768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
         #5: ffff88810bad60e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
        ...
         #46: ffff88811964d768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
         #47: ffff88811964e0e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
        INFO: lockdep is turned off.
      
      Fixing eviction to nest into ww_class_acquire is a high priority, but
      it requires a rework of the entire driver, which can only be done one
      step at a time.
      
      As an intermediate solution, add an acquire context to
      ww_mutex_trylock, which allows us to do proper nesting annotations on
      the trylocks, making the above lockdep splat disappear.
      
      This is also useful in regulator_lock_nested, which may avoid dropping
      regulator_nesting_mutex in the uncontended path, so use it there.
      
      TTM may be another user for this, where we could lock a buffer in a
      fastpath with list locks held, without dropping all locks we hold.
      
      [peterz: rework actual ww_mutex_trylock() implementations]
      Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Link: https://lkml.kernel.org/r/YUBGPdDDjKlxAuXJ@hirez.programming.kicks-ass.net
      12235da8
  8. 16 9月, 2021 1 次提交
  9. 15 9月, 2021 8 次提交