From: Oleg Nesterov Date: Wed, 26 Oct 2005 16:26:53 +0000 (+0400) Subject: [PATCH] Fix cpu timers expiration time X-Git-Tag: v2.6.14~6 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a4ed937aa44acdeb8c6ba671509dc7b54b09d3a;p=linux-2.6 [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 --- diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 2f86424fa5..383ba22f0b 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -91,7 +91,7 @@ static inline union cpu_time_count cpu_time_sub(clockid_t which_clock, * Update expiry time from increment, and increase overrun count, * given the current clock sample. */ -static inline void bump_cpu_timer(struct k_itimer *timer, +static void bump_cpu_timer(struct k_itimer *timer, union cpu_time_count now) { int i; @@ -110,7 +110,7 @@ static inline void bump_cpu_timer(struct k_itimer *timer, for (i = 0; incr < delta - incr; i++) incr = incr << 1; for (; i >= 0; incr >>= 1, i--) { - if (delta <= incr) + if (delta < incr) continue; timer->it.cpu.expires.sched += incr; timer->it_overrun += 1 << i; @@ -128,7 +128,7 @@ static inline void bump_cpu_timer(struct k_itimer *timer, for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++) incr = cputime_add(incr, incr); for (; i >= 0; incr = cputime_halve(incr), i--) { - if (cputime_le(delta, incr)) + if (cputime_lt(delta, incr)) continue; timer->it.cpu.expires.cpu = cputime_add(timer->it.cpu.expires.cpu, incr);