diff options
| author | Raghavendra K T <raghavendra.kt@amd.com> | 2023-03-01 17:49:03 +0530 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 20:03:03 -0700 |
| commit | d46031f40e0f7f7bf63914bb3f2e404ad3886ecd (patch) | |
| tree | 93792fcd0970660392d9bcbcc8c002ff02f6b7b1 | |
| parent | 20f586486b87dcfe10b8c79398e24e720885588a (diff) | |
sched/numa: use hash_32 to mix up PIDs accessing VMA
before: last 6 bits of PID is used as index to store information about
tasks accessing VMA's.
after: hash_32 is used to take of cases where tasks are created over a
period of time, and thus improve collision probability.
Result:
The patch series overall improves autonuma cost.
Kernbench around more than 5% improvement and system time in mmtest
autonuma showed more than 80% improvement
Link: https://lkml.kernel.org/r/d5a9f75513300caed74e5c8570bba9317b963c2b.1677672277.git.raghavendra.kt@amd.com
Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: Bharata B Rao <bharata@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Disha Talreja <dishaa.talreja@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/mm.h | 2 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index e05a878e186e..e249208f8fbe 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1691,7 +1691,7 @@ static inline void vma_set_access_pid_bit(struct vm_area_struct *vma) { unsigned int pid_bit; - pid_bit = current->pid % BITS_PER_LONG; + pid_bit = hash_32(current->pid, ilog2(BITS_PER_LONG)); if (vma->numab_state && !test_bit(pid_bit, &vma->numab_state->access_pids[1])) { __set_bit(pid_bit, &vma->numab_state->access_pids[1]); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a962d4b60cd7..db6fc9d978ae 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2941,7 +2941,7 @@ static bool vma_is_accessed(struct vm_area_struct *vma) return true; pids = vma->numab_state->access_pids[0] | vma->numab_state->access_pids[1]; - return test_bit(current->pid % BITS_PER_LONG, &pids); + return test_bit(hash_32(current->pid, ilog2(BITS_PER_LONG)), &pids); } #define VMA_PID_RESET_PERIOD (4 * sysctl_numa_balancing_scan_delay) |