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authorMel Gorman <mgorman@techsingularity.net>2021-06-28 19:41:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-29 10:53:54 -0700
commitdbbee9d5cd83f9d0a29639e260516907ceb2ac3d (patch)
treebb1ee3a8d0a365b8bd9abca62806e3169d5f2f12 /include/linux/mmzone.h
parent28f836b6777b6f42dce068a40d83a891deaaca37 (diff)
mm/page_alloc: convert per-cpu list protection to local_lock
There is a lack of clarity of what exactly local_irq_save/local_irq_restore protects in page_alloc.c . It conflates the protection of per-cpu page allocation structures with per-cpu vmstat deltas. This patch protects the PCP structure using local_lock which for most configurations is identical to IRQ enabling/disabling. The scope of the lock is still wider than it should be but this is decreased later. It is possible for the local_lock to be embedded safely within struct per_cpu_pages but it adds complexity to free_unref_page_list. [akpm@linux-foundation.org: coding style fixes] [mgorman@techsingularity.net: work around a pahole limitation with zero-sized struct pagesets] Link: https://lkml.kernel.org/r/20210526080741.GW30378@techsingularity.net [lkp@intel.com: Make pagesets static] Link: https://lkml.kernel.org/r/20210512095458.30632-3-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index a50b123ab7ae..0d6bb737e5a2 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -20,6 +20,7 @@
#include <linux/atomic.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
+#include <linux/local_lock.h>
#include <asm/page.h>
/* Free memory management - zoned buddy allocator. */
@@ -337,6 +338,7 @@ enum zone_watermarks {
#define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
#define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
+/* Fields and list protected by pagesets local_lock in page_alloc.c */
struct per_cpu_pages {
int count; /* number of pages in the list */
int high; /* high watermark, emptying needed */