Messages in this thread Patch in this message | | | Date | Fri, 03 Mar 2006 00:51:03 +0900 (JST) | Subject | Re: [PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem) | From | Atsushi Nemoto <> |
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>>>>> On Thu, 02 Mar 2006 23:02:27 +0900 (JST), Atsushi Nemoto <anemo@mba.ocn.ne.jp> said: anemo> In kernel 2.6, update_times() is called directly in timer anemo> interrupt, so there is no point calculating ticks here. This anemo> also get rid of difference of jiffies and jiffies_64 due to anemo> compiler's optimization (which was reported previously with anemo> subject "jiffies_64 vs. jiffies").
Sorry, it seems the patch breaks lost-tick handling on x86_64. Here is a revised patch including its adjustment.
In kernel 2.6, update_times() is called directly in timer interrupt, so there is no point calculating ticks here. This also get rid of difference of jiffies and jiffies_64 due to compiler's optimization (which was reported previously with subject "jiffies_64 vs. jiffies").
Also adjust x86_64 timer interrupt handler with this change.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 3080f84..7a1d790 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -423,7 +423,8 @@ void main_timer_handler(struct pt_regs * if (lost > 0) { handle_lost_ticks(lost, regs); - jiffies += lost; + while (lost--) + do_timer(regs); } /* diff --git a/kernel/timer.c b/kernel/timer.c index fe3a9a9..6188c99 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -906,14 +906,9 @@ void run_local_timers(void) */ static inline void update_times(void) { - unsigned long ticks; - - ticks = jiffies - wall_jiffies; - if (ticks) { - wall_jiffies += ticks; - update_wall_time(ticks); - } - calc_load(ticks); + wall_jiffies++; + update_wall_time(1); + calc_load(1); } /* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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