linux.git/fs/select.c, branch v2.6.27

Fix performance regression on lmbench select benchmark

2008-06-22T19:23:15+00:00

Christian Borntraeger reported that reinstating cond_resched() with
CONFIG_PREEMPT caused a performance regression on lmbench:

	For example select file 500:
	23 microseconds
	32 microseconds

and that's really because we totally unnecessarily do the cond_resched()
in the innermost loop of select(), which is just silly.

This moves it out from the innermost loop (which only ever loops ove the
bits in a single "unsigned long" anyway), which makes the performance
regression go away.

Reported-and-tested-by: Christian Borntraeger 
Signed-off-by: Linus Torvalds

[PATCH] split linux/file.h

2008-05-01T17:08:16+00:00

Initial splitoff of the low-level stuff; taken to fdtable.h

Signed-off-by: Al Viro

[PATCH] make osf_select() use core_sys_select()

2008-05-01T17:07:28+00:00

... instead of open-coding it

Signed-off-by: Al Viro

signals: use HAVE_SET_RESTORE_SIGMASK

2008-04-30T15:29:37+00:00

Change all the #ifdef TIF_RESTORE_SIGMASK conditionals in non-arch code to
#ifdef HAVE_SET_RESTORE_SIGMASK.  If arch code defines it first, the generic
set_restore_sigmask() using TIF_RESTORE_SIGMASK is not defined.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: "Luck, Tony" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

signals: add set_restore_sigmask

2008-04-30T15:29:37+00:00

This adds the set_restore_sigmask() inline in  and
replaces every set_thread_flag(TIF_RESTORE_SIGMASK) with a call to it.  No
change, but abstracts the details of the flag protocol from all the calls.

Signed-off-by: Roland McGrath 
Cc: Oleg Nesterov 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: "Luck, Tony" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

trivial: small cleanups

2008-04-21T22:15:06+00:00

These are small cleanups all over the tree.

Trivial style and comment changes to
  fs/select.c, kernel/signal.c, kernel/stop_machine.c & mm/pdflush.c

Signed-off-by: Pavel Machek 
Signed-off-by: Jesper Juhl

make sys_poll() wait at least timeout ms

2008-02-06T18:41:09+00:00

schedule_timeout(jiffies) waits for at least jiffies - 1.  Add 1 jiffie to
the timeout_jiffies calculated in sys_poll() to wait at least
timeout_msecs, like poll() manpage says.

Signed-off-by: Karsten Wiese 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/select, remove unused macros

2007-10-19T18:53:41+00:00

fs/select, remove unused macros

this is due to preparation for global BIT macro

Signed-off-by: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Use ERESTART_RESTARTBLOCK if poll() is interrupted by a signal

2007-10-17T15:42:53+00:00

Lomesh reported poll returning EINTR during suspend/resume cycle.  This is
caused by the STOP/CONT cycle that the freezer uses, generating a pending
signal for what in effect is an ignored signal.  In general poll is a
little eager in returning EINTR, when it could try not bother userspace and
simply restart the syscall.  Both select and ppoll do use ERESTARTNOHAND to
restart the syscall.  Oleg points out that simply using ERESTARTNOHAND will
cause poll to restart with original timeout value.  which could ultimately
lead to process never returning to userspace.  Instead use
ERESTART_RESTARTBLOCK, and restart poll with updated timeout value.
Inspired by Manfred's use ERESTARTNOHAND in poll patch.

[bunk@kernel.org: do_restart_poll() can become static]
Cc: Manfred Spraul 
Cc: Oleg Nesterov 
Cc: Roland McGrath 
Cc: "Agarwal, Lomesh" 
Signed-off-by: Chris Wright 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

do_poll: return -EINTR when signalled

2007-10-17T15:42:48+00:00

do_poll() checks signal_pending() but returns 0 when interrupted.  This means
the caller has to check signal_pending() again.

Change it to return -EINTR when signal_pending() and count == 0.

Signed-off-by: Oleg Nesterov 
Cc: Andi Kleen 
Cc: Davide Libenzi 
Cc: Vadim Lobanov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds