The patch titled
cpu-timers: return correct previous timer reload value
has been added to the -mm tree. Its filename is
cpu-timers-return-correct-previous-timer-reload-value.patch
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------------------------------------------------------
Subject: cpu-timers: return correct previous timer reload value
From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
According POSIX we need to correctly set old timer it_interval value when
user request that in timer_settime(). Tested using below program.
#include <sys/time.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <assert.h>
int main(void)
{
struct sigaction act;
struct sigevent evt = { };
timer_t tid;
struct itimerspec spec, u_spec, k_spec;
evt.sigev_notify = SIGEV_SIGNAL;
evt.sigev_signo = SIGPROF;
assert(timer_create(CLOCK_PROCESS_CPUTIME_ID, &evt, &tid) == 0);
spec.it_value.tv_sec = 1;
spec.it_value.tv_nsec = 2;
spec.it_interval.tv_sec = 3;
spec.it_interval.tv_nsec = 4;
u_spec = spec;
assert(timer_settime(tid, 0, &spec, NULL) == 0);
spec.it_value.tv_sec = 5;
spec.it_value.tv_nsec = 6;
spec.it_interval.tv_sec = 7;
spec.it_interval.tv_nsec = 8;
assert(timer_settime(tid, 0, &spec, &k_spec) == 0);
#define PRT(val) printf(#val ":\t%d/%d\n", (int) u_spec.val, (int) k_spec.val)
PRT(it_value.tv_sec);
PRT(it_value.tv_nsec);
PRT(it_interval.tv_sec);
PRT(it_interval.tv_nsec);
return 0;
}
Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Hidetoshi Seto <seto.hidetoshi@xxxxxxxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/posix-cpu-timers.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff -puN kernel/posix-cpu-timers.c~cpu-timers-return-correct-previous-timer-reload-value kernel/posix-cpu-timers.c
--- a/kernel/posix-cpu-timers.c~cpu-timers-return-correct-previous-timer-reload-value
+++ a/kernel/posix-cpu-timers.c
@@ -675,7 +675,7 @@ int posix_cpu_timer_set(struct k_itimer
struct itimerspec *new, struct itimerspec *old)
{
struct task_struct *p = timer->it.cpu.task;
- union cpu_time_count old_expires, new_expires, val;
+ union cpu_time_count old_expires, new_expires, old_incr, val;
int ret;
if (unlikely(p == NULL)) {
@@ -706,6 +706,7 @@ int posix_cpu_timer_set(struct k_itimer
BUG_ON(!irqs_disabled());
ret = 0;
+ old_incr = timer->it.cpu.incr;
spin_lock(&p->sighand->siglock);
old_expires = timer->it.cpu.expires;
if (unlikely(timer->it.cpu.firing)) {
@@ -821,7 +822,7 @@ int posix_cpu_timer_set(struct k_itimer
out:
if (old) {
sample_to_timespec(timer->it_clock,
- timer->it.cpu.incr, &old->it_interval);
+ old_incr, &old->it_interval);
}
return ret;
}
_
Patches currently in -mm which might be from sgruszka@xxxxxxxxxx are
posix-cpu-timers-reset-expire-cache-when-no-timer-is-running.patch
cpu-timers-simplify-rlimit_cpu-handling.patch
cpu-timers-cleanup-arm_timer.patch
cpu-timers-return-correct-previous-timer-reload-value.patch
cpu-timers-change-sigev_none-timer-implementation.patch
cpu-timers-assure-to-not-iterate-over-all-threads-in-fastpath_timer_check.patch
cpu-timers-optimize-run_posix_cpu_timers.patch
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