Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f1fd1067 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] Zone reclaim: resurrect may_swap 



Zone reclaim has a huge impact on NUMA performance (f.e.  our maximum
throughput with XFS is raised from 4GB to 6GB/sec / page cache contamination
of numa nodes destroys locality if one just does a large copy operation which
results in performance dropping for good until reboot).

This patch:

Resurrect may_swap in struct scan_control

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent fc301289

mm/vmscan.c

+7 −0
Original line number Diff line number Diff line
@@ -71,6 +71,9 @@ struct scan_control { 


	int may_writepage;



	/* Can pages be swapped as part of reclaim? */

	int may_swap;



	/* This context's SWAP_CLUSTER_MAX. If freeing memory for

	 * suspend, we effectively ignore SWAP_CLUSTER_MAX.

	 * In this context, it doesn't matter that we scan the
@@ -458,6 +461,8 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc) 
		 * Try to allocate it some swap space here.

		 */

		if (PageAnon(page) && !PageSwapCache(page)) {

			if (!sc->may_swap)

				goto keep_locked;

			if (!add_to_swap(page, GFP_ATOMIC))

				goto activate_locked;

		}
@@ -1166,6 +1171,7 @@ int try_to_free_pages(struct zone **zones, gfp_t gfp_mask) 


	sc.gfp_mask = gfp_mask;

	sc.may_writepage = 0;

	sc.may_swap = 1;



	inc_page_state(allocstall);
@@ -1268,6 +1274,7 @@ static int balance_pgdat(pg_data_t *pgdat, int nr_pages, int order) 
	total_reclaimed = 0;

	sc.gfp_mask = GFP_KERNEL;

	sc.may_writepage = 0;

	sc.may_swap = 1;

	sc.nr_mapped = read_page_state(nr_mapped);



	inc_page_state(pageoutrun);