diff options
| author | Raghavendra K T <raghavendra.kt@amd.com> | 2023-03-01 17:49:01 +0530 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 20:03:03 -0700 |
| commit | fc137c0ddab29b591db6a091dc6d7ce20ccb73f2 (patch) | |
| tree | 582d8a0e080aaf6b31d3cec59f65c88d8cb74e85 /mm/memory.c | |
| parent | ef6a22b70f6d90449a5c797b8968a682824e2011 (diff) | |
| download | linux-fc137c0ddab29b591db6a091dc6d7ce20ccb73f2.tar.gz | |
sched/numa: enhance vma scanning logic
During Numa scanning make sure only relevant vmas of the tasks are
scanned.
Before:
All the tasks of a process participate in scanning the vma even if they
do not access vma in it's lifespan.
Now:
Except cases of first few unconditional scans, if a process do
not touch vma (exluding false positive cases of PID collisions)
tasks no longer scan all vma
Logic used:
1) 6 bits of PID used to mark active bit in vma numab status during
fault to remember PIDs accessing vma. (Thanks Mel)
2) Subsequently in scan path, vma scanning is skipped if current PID
had not accessed vma.
3) First two times we do allow unconditional scan to preserve earlier
behaviour of scanning.
Acknowledgement to Bharata B Rao <bharata@amd.com> for initial patch to
store pid information and Peter Zijlstra <peterz@infradead.org> (Usage of
test and set bit)
Link: https://lkml.kernel.org/r/092f03105c7c1d3450f4636b1ea350407f07640e.1677672277.git.raghavendra.kt@amd.com
Signed-off-by: Raghavendra K T <raghavendra.kt@amd.com>
Suggested-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Disha Talreja <dishaa.talreja@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index 9999574a96365..f77fccb5310cb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4661,6 +4661,9 @@ int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, { get_page(page); + /* Record the current PID acceesing VMA */ + vma_set_access_pid_bit(vma); + count_vm_numa_event(NUMA_HINT_FAULTS); if (page_nid == numa_node_id()) { count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); |