| From cebbert@redhat.com Tue Nov 4 14:25:46 2008 |
| From: Ingo Molnar <mingo@elte.hu> |
| Date: Sun, 26 Oct 2008 18:21:40 -0400 |
| Subject: sched: disable the hrtick for now |
| To: stable@kernel.org |
| Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@elte.hu> |
| Message-ID: <20081026182140.371373c0@redhat.com> |
| |
| |
| From: Ingo Molnar <mingo@elte.hu> |
| |
| commit 0c4b83da58ec2e96ce9c44c211d6eac5f9dae478 upstream |
| |
| sched: disable the hrtick for now |
| |
| David Miller reported that hrtick update overhead has tripled the |
| wakeup overhead on Sparc64. |
| |
| That is too much - disable the HRTICK feature for now by default, |
| until a faster implementation is found. |
| |
| Reported-by: David Miller <davem@davemloft.net> |
| Acked-by: Peter Zijlstra <peterz@infradead.org> |
| Signed-off-by: Ingo Molnar <mingo@elte.hu> |
| Cc: Chuck Ebbert <cebbert@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| kernel/sched_features.h | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/kernel/sched_features.h |
| +++ b/kernel/sched_features.h |
| @@ -5,7 +5,7 @@ SCHED_FEAT(START_DEBIT, 1) |
| SCHED_FEAT(AFFINE_WAKEUPS, 1) |
| SCHED_FEAT(CACHE_HOT_BUDDY, 1) |
| SCHED_FEAT(SYNC_WAKEUPS, 1) |
| -SCHED_FEAT(HRTICK, 1) |
| +SCHED_FEAT(HRTICK, 0) |
| SCHED_FEAT(DOUBLE_TICK, 0) |
| SCHED_FEAT(ASYM_GRAN, 1) |
| SCHED_FEAT(LB_BIAS, 1) |
