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author | Johannes Weiner <hannes@cmpxchg.org> | 2021-03-03 06:46:58 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2021-03-06 14:40:23 +0300 |
commit | fddc8bab531e217806b84906681324377d741c6c (patch) | |
tree | 242dc5a47effff8ece67bdb77c4217f67fd5eadc | |
parent | 7fae6c8171d20ac55402930ee8ae760cf85dff7b (diff) | |
download | linux-fddc8bab531e217806b84906681324377d741c6c.tar.xz |
psi: Pressure states are unlikely
Move the unlikely branches out of line. This eliminates undesirable
jumps during wakeup and sleeps for workloads that aren't under any
sort of resource pressure.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210303034659.91735-4-zhouchengming@bytedance.com
-rw-r--r-- | kernel/sched/psi.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 0fe6ff6a6a15..3907a6b847aa 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -219,17 +219,17 @@ static bool test_state(unsigned int *tasks, enum psi_states state) { switch (state) { case PSI_IO_SOME: - return tasks[NR_IOWAIT]; + return unlikely(tasks[NR_IOWAIT]); case PSI_IO_FULL: - return tasks[NR_IOWAIT] && !tasks[NR_RUNNING]; + return unlikely(tasks[NR_IOWAIT] && !tasks[NR_RUNNING]); case PSI_MEM_SOME: - return tasks[NR_MEMSTALL]; + return unlikely(tasks[NR_MEMSTALL]); case PSI_MEM_FULL: - return tasks[NR_MEMSTALL] && !tasks[NR_RUNNING]; + return unlikely(tasks[NR_MEMSTALL] && !tasks[NR_RUNNING]); case PSI_CPU_SOME: - return tasks[NR_RUNNING] > tasks[NR_ONCPU]; + return unlikely(tasks[NR_RUNNING] > tasks[NR_ONCPU]); case PSI_CPU_FULL: - return tasks[NR_RUNNING] && !tasks[NR_ONCPU]; + return unlikely(tasks[NR_RUNNING] && !tasks[NR_ONCPU]); case PSI_NONIDLE: return tasks[NR_IOWAIT] || tasks[NR_MEMSTALL] || tasks[NR_RUNNING]; @@ -729,7 +729,7 @@ static void psi_group_change(struct psi_group *group, int cpu, * task in a cgroup is in_memstall, the corresponding groupc * on that cpu is in PSI_MEM_FULL state. */ - if (groupc->tasks[NR_ONCPU] && cpu_curr(cpu)->in_memstall) + if (unlikely(groupc->tasks[NR_ONCPU] && cpu_curr(cpu)->in_memstall)) state_mask |= (1 << PSI_MEM_FULL); groupc->state_mask = state_mask; |