diff options
| author | Mel Gorman <mgorman@techsingularity.net> | 2022-11-22 13:12:29 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-30 15:59:01 -0800 |
| commit | a4bafffb5dc5be6c7a3b77b2de0cbaf6776a3c8b (patch) | |
| tree | 04cf1f17fdbbe496d109fbeb331f5a12ef88e17b /mm/page_alloc.c | |
| parent | 5749077415994eb02d660b2559b9d8278521e73d (diff) | |
| download | lwn-a4bafffb5dc5be6c7a3b77b2de0cbaf6776a3c8b.tar.gz lwn-a4bafffb5dc5be6c7a3b77b2de0cbaf6776a3c8b.zip | |
mm/page_alloc: simplify locking during free_unref_page_list
While freeing a large list, the zone lock will be released and reacquired
to avoid long hold times since commit c24ad77d962c ("mm/page_alloc.c:
avoid excessive IRQ disabled times in free_unref_page_list()"). As
suggested by Vlastimil Babka, the lockrelease/reacquire logic can be
simplified by reusing the logic that acquires a different lock when
changing zones.
Link: https://lkml.kernel.org/r/20221122131229.5263-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 25 |
1 files changed, 9 insertions, 16 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d9d83254c485..5ab9dd29ef7e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3525,13 +3525,19 @@ void free_unref_page_list(struct list_head *list) list_del(&page->lru); migratetype = get_pcppage_migratetype(page); - /* Different zone, different pcp lock. */ - if (zone != locked_zone) { + /* + * Either different zone requiring a different pcp lock or + * excessive lock hold times when freeing a large list of + * pages. + */ + if (zone != locked_zone || batch_count == SWAP_CLUSTER_MAX) { if (pcp) { pcp_spin_unlock(pcp); pcp_trylock_finish(UP_flags); } + batch_count = 0; + /* * trylock is necessary as pages may be getting freed * from IRQ or SoftIRQ context after an IO completion. @@ -3546,7 +3552,6 @@ void free_unref_page_list(struct list_head *list) continue; } locked_zone = zone; - batch_count = 0; } /* @@ -3558,19 +3563,7 @@ void free_unref_page_list(struct list_head *list) trace_mm_page_free_batched(page); free_unref_page_commit(zone, pcp, page, migratetype, 0); - - /* - * Guard against excessive lock hold times when freeing - * a large list of pages. Lock will be reacquired if - * necessary on the next iteration. - */ - if (++batch_count == SWAP_CLUSTER_MAX) { - pcp_spin_unlock(pcp); - pcp_trylock_finish(UP_flags); - batch_count = 0; - pcp = NULL; - locked_zone = NULL; - } + batch_count++; } if (pcp) { |