renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-10 22:54:11 +08:00
Code

mm/page_alloc: simplify locking during free_unref_page_list

Browse Source 
While freeing a large list, the zone lock will be released and reacquired
to avoid long hold times since commit c24ad77d96 ("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>
This commit is contained in:
Mel Gorman 2022-11-22 13:12:29 +00:00 committed by Andrew Morton
parent 5749077415
commit a4bafffb5d
1 changed files with 9 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
mm/page_alloc.c
View File

@ -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) {