Commit be458311 authored Oct 01, 2020 by Roman Gushchin Committed by Linus Torvalds Oct 02, 2020

mm: memcg/slab: fix slab statistics in !SMP configuration



Since commit ea426c2a ("mm: memcg: prepare for byte-sized vmstat
items") the write side of slab counters accepts a value in bytes and
converts it to pages.  It happens in __mod_node_page_state().

However a non-SMP version of __mod_node_page_state() doesn't perform
this conversion.  It leads to incorrect (unrealistically high) slab
counters values.  Fix this by adding a similar conversion to the non-SMP
version of __mod_node_page_state().

Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-and-tested-by: Bastian Bittorf <bb@npl.de>
Fixes: ea426c2a ("mm: memcg: prepare for byte-sized vmstat items")
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 472e5b05

include/linux/vmstat.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -312,6 +312,11 @@ static inline void __mod_zone_page_state(struct zone *zone,
		static inline void __mod_node_page_state(struct pglist_data *pgdat,
		enum node_stat_item item, int delta)
		{
		if (vmstat_item_in_bytes(item)) {
		VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
		delta >>= PAGE_SHIFT;
		}

		node_page_state_add(delta, pgdat, item);
		}

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