posix-cpu-timers: Get rid of zero checks
Deactivation of the expiry cache is done by setting all clock caches to
0. That requires to have a check for zero in all places which update the
expiry cache:
if (cache == 0 || new < cache)
cache = new;
Use U64_MAX as the deactivated value, which allows to remove the zero
checks when updating the cache and reduces it to the obvious check:
if (new < cache)
cache = new;
This also removes the weird workaround in do_prlimit() which was required
to convert a RLIMIT_CPU value of 0 (immediate expiry) to 1 because handing
in 0 to the posix CPU timer code would have effectively disarmed it.
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Frederic Weisbecker <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 64bd10d..3ea920e 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -86,7 +86,9 @@ struct posix_cputimers {
static inline void posix_cputimers_init(struct posix_cputimers *pct)
{
- memset(pct->bases, 0, sizeof(pct->bases));
+ pct->bases[0].nextevt = U64_MAX;
+ pct->bases[1].nextevt = U64_MAX;
+ pct->bases[2].nextevt = U64_MAX;
INIT_LIST_HEAD(&pct->bases[0].cpu_timers);
INIT_LIST_HEAD(&pct->bases[1].cpu_timers);
INIT_LIST_HEAD(&pct->bases[2].cpu_timers);
@@ -102,7 +104,8 @@ static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
/* Init task static initializer */
#define INIT_CPU_TIMERBASE(b) { \
- .cpu_timers = LIST_HEAD_INIT(b.cpu_timers), \
+ .nextevt = U64_MAX, \
+ .cpu_timers = LIST_HEAD_INIT(b.cpu_timers), \
}
#define INIT_CPU_TIMERBASES(b) { \
