1. 21 9月, 2012 5 次提交
  2. 20 9月, 2012 1 次提交
    • T
      cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPU · 6889125b
      Tejun Heo 提交于
      powernowk8_target() runs off a per-cpu work item and if the
      cpufreq_policy->cpu is different from the current one, it migrates the
      kworker to the target CPU by manipulating current->cpus_allowed.  The
      function migrates the kworker back to the original CPU but this is
      still broken.  Workqueue concurrency management requires the kworkers
      to stay on the same CPU and powernowk8_target() ends up triggerring
      BUG_ON(rq != this_rq()) in try_to_wake_up_local() if it contends on
      fidvid_mutex and sleeps.
      
      It is unclear why this bug is being reported now.  Duncan says it
      appeared to be a regression of 3.6-rc1 and couldn't reproduce it on
      3.5.  Bisection seemed to point to 63d95a91 "workqueue: use @pool
      instead of @gcwq or @cpu where applicable" which is an non-functional
      change.  Given that the reproduce case sometimes took upto days to
      trigger, it's easy to be misled while bisecting.  Maybe something made
      contention on fidvid_mutex more likely?  I don't know.
      
      This patch fixes the bug by using work_on_cpu() instead if @pol->cpu
      isn't the same as the current one.  The code assumes that
      cpufreq_policy->cpu is kept online by the caller, which Rafael tells
      me is the case.
      
      stable: ed48ece2 ("workqueue: reimplement work_on_cpu() using
              system_wq") should be applied before this; otherwise, the
              behavior could be horrible.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Reported-by: NDuncan <1i5t5.duncan@cox.net>
      Tested-by: NDuncan <1i5t5.duncan@cox.net>
      Cc: Rafael J. Wysocki <rjw@sisk.pl>
      Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
      Cc: stable@vger.kernel.org
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=47301
      6889125b
  3. 19 9月, 2012 3 次提交
    • N
      md: make sure metadata is updated when spares are activated or removed. · 6dafab6b
      NeilBrown 提交于
      It isn't always necessary to update the metadata when spares are
      removed as the presence-or-not of a spare isn't really important to
      the integrity of an array.
      Also activating a spare doesn't always require updating the metadata
      as the update on 'recovery-completed' is usually sufficient.
      
      However the introduction of 'replacement' devices have made these
      transitions sometimes more important.  For example the 'Replacement'
      flag isn't cleared until the original device is removed, so we need
      to ensure a metadata update after that 'spare' is removed.
      
      So set MD_CHANGE_DEVS whenever a spare is activated or removed, to
      complement the current situation where it is set when a spare is added
      or a device is failed (or a number of other less common situations).
      
      This is suitable for -stable as out-of-data metadata could lead
      to data corruption.
      This is only relevant for 3.3 and later 9when 'replacement' as
      introduced.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: NNeilBrown <neilb@suse.de>
      6dafab6b
    • N
      md/raid5: fix calculate of 'degraded' when a replacement becomes active. · e5c86471
      NeilBrown 提交于
      When a replacement device becomes active, we mark the device that it
      replaces as 'faulty' so that it can subsequently get removed.
      However 'calc_degraded' only pays attention to the primary device, not
      the replacement, so the array appears to become degraded, which is
      wrong.
      
      So teach 'calc_degraded' to consider any replacement if a primary
      device is faulty.
      
      This is suitable for -stable as an incorrect 'degraded' value can
      confuse md and could lead to data corruption.
      This is only relevant for 3.3 and later.
      
      Cc: stable@vger.kernel.org
      Reported-by: NRobin Hill <robin@robinhill.me.uk>
      Reported-by: NJohn Drescher <drescherjm@gmail.com>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      e5c86471
    • N
      Revert "md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE." · a852d7b8
      NeilBrown 提交于
      This reverts commit 895e3c5c.
      
      While this patch seemed like a good idea and did help some workloads,
      it hurts other workloads.
      Large sequential O_DIRECT writes were faster,
      Small random O_DIRECT writes were slower.
      
      Other changes (batching RAID5 writes) have improved the sequential
      writes using a different mechanism, so the net result of this patch
      is definitely negative.  So revert it.
      Reported-by: NShaohua Li <shli@kernel.org>
      Tested-by: NJianpeng Ma <majianpeng@gmail.com>
      Signed-off-by: NNeilBrown <neilb@suse.de>
      a852d7b8
  4. 18 9月, 2012 4 次提交
  5. 16 9月, 2012 3 次提交
  6. 15 9月, 2012 3 次提交
  7. 14 9月, 2012 21 次提交