Commit de3b0150 authored Nov 30, 2019 by Johannes Weiner Committed by Linus Torvalds Dec 01, 2019

mm: vmscan: simplify lruvec_lru_size()

Patch series "mm: vmscan: cgroup-related cleanups".

Here are 8 patches that clean up the reclaim code's interaction with
cgroups a bit. They're not supposed to change any behavior, just make
the implementation easier to understand and work with.

This patch (of 8):

This function currently takes the node or lruvec size and subtracts the
zones that are excluded by the classzone index of the allocation.  It uses
four different types of counters to do this.

Just add up the eligible zones.

[cai@lca.pw: fix an undefined behavior for zone id]
  Link: http://lkml.kernel.org/r/20191108204407.1435-1-cai@lca.pw
[akpm@linux-foundation.org: deal with the MAX_NR_ZONES special case. per Qian Cai]
  Link: http://lkml.kernel.org/r/64E60F6F-7582-427B-8DD5-EF97B1656F5A@lca.pw
Link: http://lkml.kernel.org/r/20191022144803.302233-2-hannes@cmpxchg.org


Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent cb16556d

mm/vmscan.c

+5 −16

Original line number	Diff line number	Diff line
		@@ -351,32 +351,21 @@ unsigned long zone_reclaimable_pages(struct zone *zone)
		*/
		unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx)
		{
		unsigned long lru_size = 0;
		unsigned long size = 0;
		int zid;

		if (!mem_cgroup_disabled()) {
		for (zid = 0; zid < MAX_NR_ZONES; zid++)
		lru_size += mem_cgroup_get_zone_lru_size(lruvec, lru, zid);
		} else
		lru_size = node_page_state(lruvec_pgdat(lruvec), NR_LRU_BASE + lru);

		for (zid = zone_idx + 1; zid < MAX_NR_ZONES; zid++) {
		for (zid = 0; zid <= zone_idx && zid < MAX_NR_ZONES; zid++) {
		struct zone *zone = &lruvec_pgdat(lruvec)->node_zones[zid];
		unsigned long size;

		if (!managed_zone(zone))
		continue;

		if (!mem_cgroup_disabled())
		size = mem_cgroup_get_zone_lru_size(lruvec, lru, zid);
		size += mem_cgroup_get_zone_lru_size(lruvec, lru, zid);
		else
		size = zone_page_state(&lruvec_pgdat(lruvec)->node_zones[zid],
		NR_ZONE_LRU_BASE + lru);
		lru_size -= min(size, lru_size);
		size += zone_page_state(zone, NR_ZONE_LRU_BASE + lru);
		}

		return lru_size;

		return size;
		}

		/*

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