This is a squash of 2 older commits on kernel/sched.c
commit 099aa69b9cfb6f4c5b56dd1d1d06ce9ef92cf2d5
Author: Steve Muckle <smuckle@codeaurora.org>
Date: Tue Feb 28 14:07:39 2012 -0800
kernel: reduce sleep duration in wait_task_inactive
Sleeping for an entire tick adds unnecessary latency to
hotplugging a cpu (cpu_up).
Change-Id: Iab323a79f4048bc9101ecfd368e0f275827ed4ab
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
commit 52984e96358c55f89947c6de6e63d70261479f67
Author: Jeff Ohlstein <johlstei@codeaurora.org>
Date: Wed Jun 23 12:59:04 2010 -0700
sched: Extend completion api to allow io_wait time tracking
Adds a function wait_for_completion_io which behaves like
wait_for_completion, except it calls io_schedule instead of
schedule. This indicates that the process waiting on the
completion is waiting on an io event, and keeps statistics
accordingly.
Change-Id: I2514d62ff7f26441782a4cbebc4a18c07bb5ad74
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
wait_for_completion_*_timeout() can return:
0: if the wait timed out
-ve: if the wait was interrupted
+ve: if the completion was completed.
As they currently return an 'unsigned long', the last two cases
are not easily distinguished which can easily result in buggy
code, as is the case for the recently added
wait_for_completion_interruptible_timeout() call in
net/sunrpc/cache.c
So change them both to return 'long'. As MAX_SCHEDULE_TIMEOUT
is LONG_MAX, a large +ve return value should never overflow.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110105125016.64ccab0e@notabene.brown>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add more wait, wake, and completion interfaces to the device-drivers
docbook.
Fix kernel-doc notation in the added files.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add missing _killable_timeout variant for wait_for_completion that will
return when a timeout expires or the task is killed.
CC: Ingo Molnar <mingo@elte.hu>
CC: Andreas Herrmann <andreas.herrmann3@amd.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Sage Weil <sage@newdream.net>
This patch adds kernel doc for the completion feature.
An error in the split-man.pl PERL snippet in kernel-doc-nano-HOWTO.txt is
also fixed.
Signed-off-by: Kevin Diggs <kevdig@hypersurf.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
m68k fails to build with these functions inlined in completion.h. Move
them out of line into sched.c and export them to avoid this problem.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
XFS object flushing doesn't quite match existing completion semantics. It
mixed exclusive access with completion. That is, we need to mark an object as
being flushed before flushing it to disk, and then block any other attempt to
flush it until the completion occurs. We do this but adding an extra count to
the completion before we start using them. However, we still need to
determine if there is a completion in progress, and allow no-blocking attempts
fo completions to decrement the count.
To do this we introduce:
int try_wait_for_completion(struct completion *x)
returns a failure status if done == 0, otherwise decrements done
to zero and returns a "started" status. This is provided
to allow counted completions to begin safely while holding
object locks in inverted order.
int completion_done(struct completion *x)
returns 1 if there is no waiter, 0 if there is a waiter
(i.e. a completion in progress).
This replaces the use of semaphores for providing this exclusion
and completion mechanism.
SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31816a
Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Jeff Dike noticed that wait_for_completion_interruptible()'s prototype
had a mismatched fastcall.
Fix this by removing the fastcall attributes from all the completion APIs.
Found-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Clean up lockdep on-stack-completion initializer. (This also removes the
dependency on waitqueue_lock_key.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
lockdep needs to have the waitqueue lock initialized for on-stack waitqueues
implicitly initialized by DECLARE_COMPLETION(). Introduce the API.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
