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| author | Peng Liu <iwtbavbm@gmail.com> | 2020-10-08 23:48:46 +0800 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-10-29 11:00:28 +0100 |
| commit | 26762423a2664692de2bcccc9de684a5ac105e23 (patch) | |
| tree | 0228fd08fc8c15d1c1ebc2c5e96a7e42dd33cf91 /kernel/sched/sched.h | |
| parent | b9c88f752268383beff0d56e50d52b8ae62a02f8 (diff) | |
| download | lwn-26762423a2664692de2bcccc9de684a5ac105e23.tar.gz lwn-26762423a2664692de2bcccc9de684a5ac105e23.zip | |
sched/deadline: Optimize sched_dl_global_validate()
Under CONFIG_SMP, dl_bw is per root domain, but not per CPU.
When checking or updating dl_bw, currently iterating every CPU is
overdoing, just need iterate each root domain once.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/78d21ee792cc48ff79e8cd62a5f26208463684d6.1602171061.git.iwtbavbm@gmail.com
Diffstat (limited to 'kernel/sched/sched.h')
| -rw-r--r-- | kernel/sched/sched.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index df80bfcea92e..49a2daea618b 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -801,6 +801,15 @@ struct root_domain { struct dl_bw dl_bw; struct cpudl cpudl; + /* + * Indicate whether a root_domain's dl_bw has been checked or + * updated. It's monotonously increasing value. + * + * Also, some corner cases, like 'wrap around' is dangerous, but given + * that u64 is 'big enough'. So that shouldn't be a concern. + */ + u64 visit_gen; + #ifdef HAVE_RT_PUSH_IPI /* * For IPI pull requests, loop across the rto_mask. |