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  1. 19 Nov, 2009 13 commits
    • David Howells's avatar
      FS-Cache: Annotate slow-work runqueue proc lines for FS-Cache work items · 440f0aff
      David Howells authored 
      Annotate slow-work runqueue proc lines for FS-Cache work items.  Objects
include the object ID and the state.  Operations include the object ID, the
operation ID and the operation type and state.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      440f0aff
    • David Howells's avatar
      SLOW_WORK: Allow a requeueable work item to sleep till the thread is needed · 3bde31a4
      David Howells authored 
      Add a function to allow a requeueable work item to sleep till the thread
processing it is needed by the slow-work facility to perform other work.

Sometimes a work item can't progress immediately, but must wait for the
completion of another work item that's currently being processed by another
slow-work thread.

In some circumstances, the waiting item could instead - theoretically - put
itself back on the queue and yield its thread back to the slow-work facility,
thus waiting till it gets processing time again before attempting to progress.
This would allow other work items processing time on that thread.

However, this only works if there is something on the queue for it to queue
behind - otherwise it will just get a thread again immediately, and will end
up cycling between the queue and the thread, eating up valuable CPU time.

So, slow_work_sleep_till_thread_needed() is provided such that an item can put
itself on a wait queue that will wake it up when the event it is actually
interested in occurs, then call this function in lieu of calling schedule().

This function will then sleep until either the item's event occurs or another
work item appears on the queue.  If another work item is queued, but the
item's event hasn't occurred, then the work item should requeue itself and
yield the thread back to the slow-work facility by returning.

This can be used by CacheFiles for an object that is being created on one
thread to wait for an object being deleted on another thread where there is
nothing on the queue for the creation to go and wait behind.  As soon as an
item appears on the queue that could be given thread time instead, CacheFiles
can stick the creating object back on the queue and return to the slow-work
facility - assuming the object deletion didn't also complete.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      3bde31a4
    • David Howells's avatar
      SLOW_WORK: Allow the owner of a work item to determine if it is queued or not · 31ba99d3
      David Howells authored 
      Add a function (slow_work_is_queued()) to permit the owner of a work item to
determine if the item is queued or not.

The work item is counted as being queued if it is actually on the queue, not
just if it is pending.  If it is executing and pending, then it is not on the
queue, but will rather be put back on the queue when execution finishes.

This permits a caller to quickly work out if it may be able to put another,
dependent work item on the queue behind it, or whether it will have to wait
till that is finished.

This can be used by CacheFiles to work out whether the creation a new object
can be immediately deferred when it has to wait for an old object to be
deleted, or whether a wait must take place.  If a wait is necessary, then the
slow-work thread can otherwise get blocked, preventing the deletion from
taking place.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      31ba99d3
    • David Howells's avatar
      SLOW_WORK: Allow the work items to be viewed through a /proc file · 8fba10a4
      David Howells authored 
      Allow the executing and queued work items to be viewed through a /proc file
for debugging purposes.  The contents look something like the following:

    THR PID   ITEM ADDR        FL MARK  DESC
    === ===== ================ == ===== ==========
      0  3005 ffff880023f52348  a 952ms FSC: OBJ17d3: LOOK
      1  3006 ffff880024e33668  2 160ms FSC: OBJ17e5 OP60d3b: Write1/Store fl=2
      2  3165 ffff8800296dd180  a 424ms FSC: OBJ17e4: LOOK
      3  4089 ffff8800262c8d78  a 212ms FSC: OBJ17ea: CRTN
      4  4090 ffff88002792bed8  2 388ms FSC: OBJ17e8 OP60d36: Write1/Store fl=2
      5  4092 ffff88002a0ef308  2 388ms FSC: OBJ17e7 OP60d2e: Write1/Store fl=2
      6  4094 ffff88002abaf4b8  2 132ms FSC: OBJ17e2 OP60d4e: Write1/Store fl=2
      7  4095 ffff88002bb188e0  a 388ms FSC: OBJ17e9: CRTN
    vsq     - ffff880023d99668  1 308ms FSC: OBJ17e0 OP60f91: Write1/EnQ fl=2
    vsq     - ffff8800295d1740  1 212ms FSC: OBJ16be OP4d4b6: Write1/EnQ fl=2
    vsq     - ffff880025ba3308  1 160ms FSC: OBJ179a OP58dec: Write1/EnQ fl=2
    vsq     - ffff880024ec83e0  1 160ms FSC: OBJ17ae OP599f2: Write1/EnQ fl=2
    vsq     - ffff880026618e00  1 160ms FSC: OBJ17e6 OP60d33: Write1/EnQ fl=2
    vsq     - ffff880025a2a4b8  1 132ms FSC: OBJ16a2 OP4d583: Write1/EnQ fl=2
    vsq     - ffff880023cbe6d8  9 212ms FSC: OBJ17eb: LOOK
    vsq     - ffff880024d37590  9 212ms FSC: OBJ17ec: LOOK
    vsq     - ffff880027746cb0  9 212ms FSC: OBJ17ed: LOOK
    vsq     - ffff880024d37ae8  9 212ms FSC: OBJ17ee: LOOK
    vsq     - ffff880024d37cb0  9 212ms FSC: OBJ17ef: LOOK
    vsq     - ffff880025036550  9 212ms FSC: OBJ17f0: LOOK
    vsq     - ffff8800250368e0  9 212ms FSC: OBJ17f1: LOOK
    vsq     - ffff880025036aa8  9 212ms FSC: OBJ17f2: LOOK

In the 'THR' column, executing items show the thread they're occupying and
queued threads indicate which queue they're on.  'PID' shows the process ID of
a slow-work thread that's executing something.  'FL' shows the work item flags.
'MARK' indicates how long since an item was queued or began executing.  Lastly,
the 'DESC' column permits the owner of an item to give some information.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      8fba10a4
    • Jens Axboe's avatar
      SLOW_WORK: Add delayed_slow_work support · 6b8268b1
      Jens Axboe authored 
      This adds support for starting slow work with a delay, similar
to the functionality we have for workqueues.
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      6b8268b1
    • Jens Axboe's avatar
      SLOW_WORK: Add support for cancellation of slow work · 01609502
      Jens Axboe authored 
      Add support for cancellation of queued slow work and delayed slow work items.
The cancellation functions will wait for items that are pending or undergoing
execution to be discarded by the slow work facility.

Attempting to enqueue work that is in the process of being cancelled will
result in ECANCELED.
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      01609502
    • Jens Axboe's avatar
      SLOW_WORK: Make slow_work_ops ->get_ref/->put_ref optional · 4d8bb2cb
      Jens Axboe authored 
      Make the ability for the slow-work facility to take references on a work item
optional as not everyone requires this.

Even the internal slow-work stubs them out, so those can be got rid of too.
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      4d8bb2cb
    • David Howells's avatar
      SLOW_WORK: Wait for outstanding work items belonging to a module to clear · 3d7a641e
      David Howells authored 
      Wait for outstanding slow work items belonging to a module to clear when
unregistering that module as a user of the facility.  This prevents the put_ref
code of a work item from being taken away before it returns.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      3d7a641e
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq · 66b00a7c
      Linus Torvalds authored 
      * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Fix stale cpufreq_cpu_governor pointer
  [CPUFREQ] Resolve time unit thinko in ondemand/conservative govs
  [CPUFREQ] speedstep-ich: fix error caused by 394122ab
  [CPUFREQ] Fix use after free on governor restore
  [CPUFREQ] acpi-cpufreq: blacklist Intel 0f68: Fix HT detection and put in notification message
  [CPUFREQ] powernow-k8: Fix test in get_transition_latency()
  [CPUFREQ] longhaul: select Longhaul version 2 for capable CPUs
      66b00a7c
    • Linus Torvalds's avatar
      strcmp: fix overflow and possibly signedness error · a414f01a
      Linus Torvalds authored 
      Doing the strcmp return value as

	signed char __res = *cs - *ct;

is wrong for two reasons.  The subtraction can overflow because __res
doesn't use a type big enough.  Moreover the compared bytes should be
interpreted as unsigned char as specified by POSIX.

The same problem is fixed in strncmp.
Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a414f01a
    • Linus Torvalds's avatar
      Merge branch 'agp-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6 · 6602b355
      Linus Torvalds authored 
      * 'agp-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
  agp/intel-agp: Set dma_mask for capable chipsets before agp_add_bridge()
      6602b355
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of... · 7f6f3507
      Linus Torvalds authored 
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  ima: replace GFP_KERNEL with GFP_NOFS
      7f6f3507
    • David Woodhouse's avatar
      agp/intel-agp: Set dma_mask for capable chipsets before agp_add_bridge() · ec402ba9
      David Woodhouse authored 
      We should set this before calling agp_add_bridge() so that it's done
before we map the scratch page too.

This should probably fix the regression reported as k.o. bug #14627.
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      ec402ba9
  3. 18 Nov, 2009 27 commits
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