1. 04 7月, 2018 2 次提交
  2. 03 7月, 2018 2 次提交
    • T
      drm: Change deadlock-avoidance algorithm for the modeset locks. · 07c13bb7
      Thomas Hellstrom 提交于
      For modeset locks we don't expect a high number of contending
      transactions so change algorithm from Wait-Die to Wound-Wait.
      
      Cc: dri-devel@lists.freedesktop.org
      Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
      Acked-by: NIngo Molnar <mingo@kernel.org>
      07c13bb7
    • T
      locking: Implement an algorithm choice for Wound-Wait mutexes · 08295b3b
      Thomas Hellstrom 提交于
      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: NPeter Zijlstra <peterz@infradead.org>
      Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
      Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: NIngo Molnar <mingo@kernel.org>
      08295b3b
  3. 28 6月, 2018 17 次提交
  4. 27 6月, 2018 2 次提交
  5. 26 6月, 2018 5 次提交
  6. 25 6月, 2018 4 次提交
  7. 22 6月, 2018 4 次提交
  8. 21 6月, 2018 4 次提交