linux-toradex.git/include/linux/poll.h, branch v2.6.38.5

poll: fix a typo in comment

2010-12-10T14:06:43+00:00

Convert duplicated sys_poll to select. As Kosaki suggests, sys_poll() and
sys_select() are now hidden by SYSCALL_DEFINEx() macros so it would be
better to use plain select/poll syscall name.

Signed-off-by: Namhyung Kim 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Jiri Kosina

epoll: make epoll_wait() use the hrtimer range feature

2010-10-28T01:03:18+00:00

This make epoll use hrtimers for the timeout value which prevents
epoll_wait() from timing out up to a millisecond early.

This mirrors the behavior of select() and poll().

Signed-off-by: Shawn Bohrer 
Cc: Al Viro 
Acked-by: Davide Libenzi 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sysctl extern cleanup: poll

2010-03-12T23:53:11+00:00

Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move epoll_table extern declaration to linux/poll.h

Signed-off-by: Dave Young 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

headers: remove sched.h from poll.h

2009-10-04T22:05:10+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

poll: avoid extra wakeups in select/poll

2009-06-17T02:47:48+00:00

After introduction of keyed wakeups Davide Libenzi did on epoll, we are
able to avoid spurious wakeups in poll()/select() code too.

For example, typical use of poll()/select() is to wait for incoming
network frames on many sockets.  But TX completion for UDP/TCP frames call
sock_wfree() which in turn schedules thread.

When scheduled, thread does a full scan of all polled fds and can sleep
again, because nothing is really available.  If number of fds is large,
this cause significant load.

This patch makes select()/poll() aware of keyed wakeups and useless
wakeups are avoided.  This reduces number of context switches by about 50%
on some setups, and work performed by sofirq handlers.

Signed-off-by: Eric Dumazet 
Acked-by: David S. Miller 
Acked-by: Andi Kleen 
Acked-by: Ingo Molnar 
Acked-by: Davide Libenzi 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

poll: allow f_op->poll to sleep

2009-01-06T23:59:12+00:00

f_op->poll is the only vfs operation which is not allowed to sleep.  It's
because poll and select implementation used task state to synchronize
against wake ups, which doesn't have to be the case anymore as wait/wake
interface can now use custom wake up functions.  The non-sleep restriction
can be a bit tricky because ->poll is not called from an atomic context
and the result of accidentally sleeping in ->poll only shows up as
temporary busy looping when the timing is right or rather wrong.

This patch converts poll/select to use custom wake up function and use
separate triggered variable to synchronize against wake up events.  The
only added overhead is an extra function call during wake up and
negligible.

This patch removes the one non-sleep exception from vfs locking rules and
is beneficial to userland filesystem implementations like FUSE, 9p or
peculiar fs like spufs as it's very difficult for those to implement
non-sleeping poll method.

While at it, make the following cosmetic changes to make poll.h and
select.c checkpatch friendly.

* s/type * symbol/type *symbol/		   : three places in poll.h
* remove blank line before EXPORT_SYMBOL() : two places in select.c

Oleg: spotted missing barrier in poll_schedule_timeout()
Davide: spotted missing write barrier in pollwake()

Signed-off-by: Tejun Heo 
Cc: Eric Van Hensbergen 
Cc: Ron Minnich 
Cc: Ingo Molnar 
Cc: Christoph Hellwig 
Signed-off-by: Miklos Szeredi 
Cc: Davide Libenzi 
Cc: Brad Boyer 
Cc: Al Viro 
Cc: Roland McGrath 
Cc: Mauro Carvalho Chehab 
Signed-off-by: Andrew Morton 
Cc: Davide Libenzi 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

select: switch select() and poll() over to hrtimers

2008-09-06T04:35:03+00:00

With lots of help, input and cleanups from Thomas Gleixner

This patch switches select() and poll() over to hrtimers.

The core of the patch is replacing the "s64 timeout" with a
"struct timespec end_time" in all the plumbing.

But most of the diffstat comes from using the just introduced helpers:
	poll_select_set_timeout
	poll_select_copy_remaining
	timespec_add_safe
which make manipulating the timespec easier and less error-prone.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Thomas Gleixner

select: add poll_select_set_timeout() and poll_select_copy_remaining() helpers

2008-09-06T04:34:59+00:00

This patch adds 2 helpers that will be used for the hrtimer based select/poll:

poll_select_set_timeout() is a helper that takes a timeout (as a second, nanosecond
pair) and turns that into a "struct timespec" that represents the absolute end time.
This is a common operation in the many select() and poll() variants and needs various,
common, sanity checks.

poll_select_copy_remaining() is a helper that takes care of copying the remaining
time to userspace, as select(), pselect() and ppoll() do. This function comes in
both a natural and a compat implementation (due to datastructure differences).

Signed-off-by: Thomas Gleixner 
Signed-off-by: Arjan van de Ven

[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

Fix select on /proc files without ->poll

2007-09-12T00:21:20+00:00

Taneli Vähäkangas  reported that commit
786d7e1612f0b0adb6046f19b906609e4fe8b1ba aka "Fix rmmod/read/write races
in /proc entries" broke SBCL + SLIME combo.

The old code in do_select() used DEFAULT_POLLMASK, if couldn't find
->poll handler.  The new code makes ->poll always there and returns 0 by
default, which is not correct.  Return DEFAULT_POLLMASK instead.

Steps to reproduce:

	install emacs, SBCL, SLIME
	emacs
	M-x slime	in *inferior-lisp* buffer
	[watch it doing "Connecting to Swank on port X.."]

Please, apply before 2.6.23.

P.S.: why SBCL can't just read(2) /proc/cpuinfo is a mystery.

Signed-off-by: Alexey Dobriyan 
Cc: T Taneli Vahakangas 
Cc: Oleg Nesterov 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds