diff options
| author | Pavel Emelyanov <xemul@parallels.com> | 2013-03-11 13:12:21 +0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2013-04-17 20:51:01 +0200 |
| commit | 5ed67f05f66c41e39880a6d61358438a25f9fee5 (patch) | |
| tree | d3e52cca63e119a1f437b660f5d7a553f8ee37bc /include/linux/sched.h | |
| parent | 4e8f8b34b92b6514cc070aeb94d317cadd5071d7 (diff) | |
posix timers: Allocate timer id per process (v2)
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 <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Link: http://lkml.kernel.org/r/513D9FF5.9010004@parallels.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index d35d2b6ddbf..d13341b5509 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -526,7 +526,8 @@ struct signal_struct { unsigned int has_child_subreaper:1; /* POSIX.1b Interval Timers */ - struct list_head posix_timers; + int posix_timer_id; + struct list_head posix_timers; /* ITIMER_REAL timer for the process */ struct hrtimer real_timer; |