Messages in this thread | | | Date | Wed, 31 Dec 2008 14:08:45 -0800 | From | Mike Travis <> | Subject | tip/master merge problem? |
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Hi Ingo,
I found this code snippet in kernel/sched.c in the tip/master tree. It appears to be a merge mistake: (cut and pasted - no tabs)
292 /* 293 * If this cpu is the one which updates jiffies, then 294 * give up the assignment and let it be taken by the 295 * cpu which runs the tick timer next, which might be 296 * this cpu as well. If we don't drop this here the 297 * jiffies might be stale and do_timer() never 298 * invoked. 299 */ 300 if (cpu == tick_do_timer_cpu) 301 tick_do_timer_cpu = TICK_DO_TIMER_NONE; 302 303 if (delta_jiffies > 1) 304 305 /* Skip reprogram of event if its not changed */ 306 if (ts->tick_stopped && ktime_equal(expires, dev->next_event)) 307 goto out; 308 309 cpumask_set_cpu(cpu, nohz_cpu_mask);
I think the "Skip reprogram" was inserted into the middle of a previous if-then statement.
git blames it on: 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 292) /* 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 293) * If this cpu is the one which updates jiffies, then 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 294) * give up the assignment and let it be taken by the 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 295) * cpu which runs the tick timer next, which might be 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 296) * this cpu as well. If we don't drop this here the 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 297) * jiffies might be stale and do_timer() never 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 298) * invoked. 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 299) */ 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 300) if (cpu == tick_do_timer_cpu) 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 301) tick_do_timer_cpu = TICK_DO_TIMER_NONE; 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 302) 6ba9b346 (Ingo Molnar 2007-02-19 18:11:56 +0000 303) if (delta_jiffies > 1) 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 304) 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 305) /* Skip reprogram of event if its not changed */ 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 306) if (ts->tick_stopped && ktime_equal(expires, dev->next_event)) 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 307) goto out; 00147449 (Woodruff, Richard 2008-12-01 14:18:11 -0800 308) 6a7b3dc3 (Rusty Russell 2008-11-25 02:35:04 +1030 309) cpumask_set_cpu(cpu, nohz_cpu_mask);
I've Cc'd both interested parties.
Thanks, Mike
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