From dbbee9d5cd83f9d0a29639e260516907ceb2ac3d Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 28 Jun 2021 19:41:41 -0700 Subject: 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 Acked-by: Vlastimil Babka Acked-by: Peter Zijlstra (Intel) Cc: Chuck Lever Cc: Ingo Molnar Cc: Jesper Dangaard Brouer Cc: Michal Hocko Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') 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 #include #include +#include #include /* 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 */ -- cgit v1.2.3