On Thu, Aug 23, 2007 at 08:57:32AM -0700, Sven-Thorsten Dietrich wrote: | On Thu, 2007-08-23 at 17:51 +0200, Ingo Molnar wrote: | > * Sven-Thorsten Dietrich <sven@xxxxxxxxxxxxxxxxxxxxx> wrote: | > | > > On Thu, 2007-08-16 at 21:37 -0300, Luis Claudio R. Goncalves wrote: | > > > Hello, | > > > | > > > The values in /proc/loadavgrt are sometimes the real load and sometimes | > > > garbage. As you can see in th tests below, it occurs from in 2.6.21.5-rt20 | > > > to 2.6.23-rc2-rt2. The code for calc_load(), in kernel/timer.c has not | > > > changed much in -rt patches. ... | > > > active_tasks = count_active_tasks(); | > > > + active_rt_tasks = count_active_rt_tasks(); | > > | > > Where is this used? | > | > what is "this"? /proc/loadavg? Or the code/patch you quoted? | | active_rt_tasks Good point! I misspelled it in my first patch. This one should be better! ----------> Fixes spurious system load spikes observed in /proc/loadavgrt, as described in: Bug 253103: /proc/loadavgrt issues weird results https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=253103 Signed-off-by: Luis Claudio R. Goncalves <lclaudio@xxxxxxxx> --- diff --git a/kernel/sched.c b/kernel/sched.c index 811a502..c61609a 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2520,6 +2520,13 @@ unsigned long rt_nr_uninterruptible(void) for_each_online_cpu(i) sum += cpu_rq(i)->rt_nr_uninterruptible; + /* + * Since we read the counters lockless, it might be slightly + * inaccurate. Do not allow it to go below zero though: + */ + if (unlikely((long)sum < 0)) + sum = 0; + return sum; } diff --git a/kernel/timer.c b/kernel/timer.c index 882ca9d..0e49bf6 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1432,23 +1432,25 @@ unsigned long avenrun_rt[3]; static inline void calc_load(unsigned long ticks) { unsigned long active_tasks; /* fixed-point */ + unsigned long active_rt_tasks; /* fixed-point */ static int count = LOAD_FREQ; count -= ticks; if (unlikely(count < 0)) { active_tasks = count_active_tasks(); + active_rt_tasks = count_active_rt_tasks(); do { CALC_LOAD(avenrun[0], EXP_1, active_tasks); CALC_LOAD(avenrun[1], EXP_5, active_tasks); CALC_LOAD(avenrun[2], EXP_15, active_tasks); - count += LOAD_FREQ; - } while (count < 0); #ifdef CONFIG_PREEMPT_RT - active_tasks = count_active_rt_tasks(); - CALC_LOAD(avenrun_rt[0], EXP_1, active_tasks); - CALC_LOAD(avenrun_rt[1], EXP_5, active_tasks); - CALC_LOAD(avenrun_rt[2], EXP_15, active_tasks); + CALC_LOAD(avenrun_rt[0], EXP_1, active_rt_tasks); + CALC_LOAD(avenrun_rt[1], EXP_5, active_rt_tasks); + CALC_LOAD(avenrun_rt[2], EXP_15, active_rt_tasks); #endif + count += LOAD_FREQ; + + } while (count < 0); } } - -- - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
