linux.git/kernel/posix-timers.c, branch master

time/timers: Move all time(r) related files into kernel/time

2014-06-23T09:22:35+00:00

Except for Kconfig.HZ. That needs a separate treatment.

Signed-off-by: Thomas Gleixner

posix-timers: Remove unused variable

2013-04-18T10:51:19+00:00

Remove the unused variable *node introduced by commit 5ed67f05 (posix
timers: Allocate timer id per process)

Signed-off-by: Thomas Gleixner 
Cc: Pavel Emelyanov

posix timers: Allocate timer id per process (v2)

2013-04-17T18:51:01+00:00

Currently kernel generates IDs for posix timers in a global manner --
there's a kernel-wide IDR tree from which IDs are created. This makes
it impossible to recreate a timer with a desired ID (in particular
this is done by the CRIU checkpoint-restore project) -- since these
IDs are global it may happen, that at the time we recreate a timer, the
ID we want for it is already busy by some other timer.

In order to address this, replace the IDR tree with a global hash
table for timers and makes timer IDs unique per signal_struct (to
which timers are linked anyway). With this, two timers belonging to
different processes may have equal IDs and we can recreate either of
them with the ID we want.

Signed-off-by: Pavel Emelyanov 
Cc: Peter Zijlstra 
Cc: Michael Kerrisk 
Cc: Matthew Helsley 
Link: http://lkml.kernel.org/r/513D9FF5.9010004@parallels.com
Signed-off-by: Thomas Gleixner

hrtimer: Add hrtimer support for CLOCK_TAI

2013-03-22T23:19:59+00:00

Add hrtimer support for CLOCK_TAI, as well as posix timer interfaces.

Signed-off-by: John Stultz

timekeeping: Add CLOCK_TAI clockid

2013-03-22T23:19:59+00:00

This add a CLOCK_TAI clockid and the needed accessors.

CC: Thomas Gleixner 
CC: Eric Dumazet 
CC: Richard Cochran 
Signed-off-by: John Stultz

posix-timers: convert to idr_alloc()

2013-02-28T03:10:19+00:00

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

posix-timer: Don't call idr_find() with out-of-range ID

2013-02-21T16:28:29+00:00

When idr_find() was fed a negative ID, it used to look up the ID
ignoring the sign bit before recent ("idr: remove MAX_IDR_MASK and
move left MAX_IDR_* into idr.c") patch. Now a negative ID triggers
a WARN_ON_ONCE().

__lock_timer() feeds timer_id from userland directly to idr_find()
without sanitizing it which can trigger the above malfunctions.  Add a
range check on @timer_id before invoking idr_find() in __lock_timer().

While timer_t is defined as int by all archs at the moment, Andrew
worries that it may be defined as a larger type later on.  Make the
test cover larger integers too so that it at least is guaranteed to
not return the wrong timer.

Note that WARN_ON_ONCE() in idr_find() on id < 0 is transitional
precaution while moving away from ignoring MSB.  Once it's gone we can
remove the guard as long as timer_t isn't larger than int.

Signed-off-by: Tejun Heo nnn
Reported-by: Sasha Levin 
Cc: Andrew Morton 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20130220232412.GL3570@htj.dyndns.org
Signed-off-by: Thomas Gleixner

posix-timers: Fix clock_adjtime to always return timex data on success

2013-01-16T02:16:07+00:00

The clock_adj call returns the clock state on success, which may be a
non-zero value (e.g. TIME_INS), but the modified timex data is copied
back to the user only when zero value (TIME_OK) was returned. Fix the
condition to copy the data also with positive return values.

Signed-off-by: Miroslav Lichvar 
Signed-off-by: John Stultz

kernel: Map most files to use export.h instead of module.h

2011-10-31T13:20:12+00:00

The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

  -#include 
  +#include 

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker

posix-timers: RCU conversion

2011-05-24T10:10:51+00:00

Ben Nagy reported a scalability problem with KVM/QEMU that hit very hard
a single spinlock (idr_lock) in posix-timers code, on its 48 core
machine.

Even on a 16 cpu machine (2x4x2), a single test can show 98% of cpu time
used in ticket_spin_lock, from lock_timer

Ref: http://www.spinics.net/lists/kvm/msg51526.html

Switching to RCU is quite easy, IDR being already RCU ready. idr_lock
should be locked only for an insert/delete, not a lookup.

Benchmark on a 2x4x2 machine, 16 processes calling timer_gettime().

Before :

real    1m18.669s
user    0m1.346s
sys     1m17.180s

After :

real    0m3.296s
user    0m1.366s
sys     0m1.926s

Reported-by: Ben Nagy 
Signed-off-by: Eric Dumazet 
Tested-by: Ben Nagy 
Cc: Oleg Nesterov 
Cc: Avi Kivity 
Cc: John Stultz 
Cc: Richard Cochran 
Cc: Paul E. McKenney 
Cc: Andrew Morton 
Signed-off-by: Thomas Gleixner