linux-toradex.git/fs/timerfd.c, branch v3.17-rc6

timerfd: Use ktime_mono_to_real()

2014-07-23T17:18:02+00:00

We have a few other use cases of ktime_get_monotonic_offset() which
can be optimized with ktime_mono_to_real(). The timerfd code uses the
offset only for comparison, so we can use ktime_mono_to_real(0) for
this as well.

Funny enough text size shrinks with that on ARM and x8664 !?

Signed-off-by: Thomas Gleixner 
Signed-off-by: John Stultz

timerfd: Implement timerfd_ioctl method to restore timerfd_ctx::ticks, v3

2014-07-18T09:49:57+00:00

The read() of timerfd files allows to fetch the number of timer ticks
while there is no way to set it back from userspace.

To restore the timer's state as it was at checkpoint moment we need
a path to bring @ticks back. Initially I thought about writing ticks
back via write() interface but it seems such API is somehow obscure.

Instead implement timerfd_ioctl() method with TFD_IOC_SET_TICKS
command which allows to adjust @ticks into non-zero value waking
up the waiters.

I wrapped code with CONFIG_CHECKPOINT_RESTORE which can be
dropped off if there users except c/r camp appear.

v2 (by akpm@):
 - Use define timerfd_ioctl NULL for non c/r config

v3:
 - Use copy_from_user for @ticks fetching since
   not all arch support get_user for 8 byte argument

Signed-off-by: Cyrill Gorcunov 
Cc: Andrew Morton 
Cc: Michael Kerrisk 
Cc: Andrey Vagin 
Cc: Arnd Bergmann 
Cc: Christopher Covington 
Cc: Pavel Emelyanov 
Cc: Vladimir Davydov 
Link: http://lkml.kernel.org/r/20140715215703.285617923@openvz.org
Signed-off-by: Thomas Gleixner

timerfd: Implement show_fdinfo method

2014-07-18T09:49:57+00:00

For checkpoint/restore of timerfd files we need to know how exactly
the timer were armed, to be able to recreate it on restore stage.
Thus implement show_fdinfo method which provides enough information
for that.

One of significant changes I think is the addition of @settime_flags
member. Currently there are two flags TFD_TIMER_ABSTIME and
TFD_TIMER_CANCEL_ON_SET, and the second can be found from
@might_cancel variable but in case if the flags will be extended
in future we most probably will have to somehow remember them
explicitly anyway so I guss doing that right now won't hurt.

To not bloat the timerfd_ctx structure I've converted @expired
to short integer and defined @settime_flags as short too.

v2 (by avagin@, vdavydov@ and tglx@):

 - Add it_value/it_interval fields
 - Save flags being used in timerfd_setup in context

v3 (by tglx@):
 - don't forget to use CONFIG_PROC_FS

v4 (by akpm@):
 -Use define timerfd_show NULL for non c/r config

Signed-off-by: Cyrill Gorcunov 
Cc: Andrew Morton 
Cc: Michael Kerrisk 
Cc: Andrey Vagin 
Cc: Pavel Emelyanov 
Cc: Vladimir Davydov 
Link: http://lkml.kernel.org/r/20140715215703.114365649@openvz.org
Signed-off-by: Thomas Gleixner

timerfd: support CLOCK_BOOTTIME clock

2014-01-24T00:57:40+00:00

Add CLOCK_BOOTTIME support to timerfd

Signed-off-by: Greg Hackmann 
Signed-off-by: John Stultz

timerfd: Add alarm timers

2013-05-29T19:57:34+00:00

Add support for clocks CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM,
thereby enabling wakeup alarm timers via file descriptors.

Signed-off-by: Todd Poynor 
Signed-off-by: John Stultz

compat: restore timerfd settime and gettime compat syscalls

2013-03-02T14:35:13+00:00

Both compat syscalls got lost with 9d94b9e2 "switch timerfd compat syscalls
to COMPAT_SYSCALL_DEFINE" because of a typo:
COMPAT instead of CONFIG_COMPAT.

Signed-off-by: Heiko Carstens 
Signed-off-by: Al Viro

switch timerfd compat syscalls to COMPAT_SYSCALL_DEFINE

2013-02-03T20:09:25+00:00

... and move them over to fs/timerfd.c.  Cleaner and easier
that way...

Signed-off-by: Al Viro

switch simple cases of fget_light to fdget

2012-09-27T02:20:08+00:00

Signed-off-by: Al Viro

switch timerfd_[sg]ettime(2) to fget_light()

2012-09-27T01:10:08+00:00

Signed-off-by: Al Viro

timerfd: Fix wakeup of processes when timer is cancelled on clock change

2011-06-14T09:46:14+00:00

Currently processes waiting with poll on cancelable timerfd timers are
not woken up when the timers are canceled. When the system time is set
the clock_was_set() function calls timerfd_clock_was_set() to cancel
and wake up processes waiting on potential cancelable timerfd
timers. However the wake up currently has no effect because in the
case of timerfd_read it is dependent on ctx->ticks not being
0. timerfd_poll also requires ctx->ticks being non zero. As a
consequence processes waiting on cancelable timers only get woken up
when the timers expire. This patch fixes this by incrementing
ctx->ticks before calling wake_up.

Signed-off-by: Max Asbock 
Cc: kay.sievers@vrfy.org
Cc: virtuoso@slind.org
Cc: johnstul 
Link: http://lkml.kernel.org/r/1307985512.4710.41.camel@w-amax.beaverton.ibm.com
Signed-off-by: Thomas Gleixner