Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
[PATCH] Fix cpu timers expiration time
There's a silly off-by-one error in the code that updates the expiration
of posix CPU timers, causing them to not be properly updated when they
hit exactly on their expiration time (which should be the normal case).
This causes them to then fire immediately again, and only _then_ get
properly updated.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
authored by
Oleg Nesterov
and committed by
Linus Torvalds
7a4ed937
e02fd440
+3
-3
+3
-3
kernel/posix-cpu-timers.c
+3
-3
kernel/posix-cpu-timers.c
···
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* Update expiry time from increment, and increase overrun count,
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* given the current clock sample.
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*/
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-
static inline void bump_cpu_timer(struct k_itimer *timer,
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+
static void bump_cpu_timer(struct k_itimer *timer,
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union cpu_time_count now)
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{
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int i;
···
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for (i = 0; incr < delta - incr; i++)
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incr = incr << 1;
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for (; i >= 0; incr >>= 1, i--) {
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-
if (delta <= incr)
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+
if (delta < incr)
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continue;
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timer->it.cpu.expires.sched += incr;
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timer->it_overrun += 1 << i;
···
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for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
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incr = cputime_add(incr, incr);
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for (; i >= 0; incr = cputime_halve(incr), i--) {
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-
if (cputime_le(delta, incr))
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+
if (cputime_lt(delta, incr))
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continue;
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timer->it.cpu.expires.cpu =
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cputime_add(timer->it.cpu.expires.cpu, incr);