Commit 61dc4358 authored by Adrian Huang (Lenovo)'s avatar Adrian Huang (Lenovo) Committed by Andrew Morton
Browse files

mm: correct misleading comment on mmap_lock field in mm_struct 

The comment previously described the offset of mmap_lock as 0x120 (hex),
which is misleading.  The correct offset is 56 bytes (decimal) from the
last cache line boundary.  Using '0x120' could confuse readers trying to
understand why the count and owner fields reside in separate cachelines.

This change also removes an unnecessary space for improved formatting.

Link: https://lkml.kernel.org/r/20250806145906.24647-1-adrianhuang0701@gmail.com


Signed-off-by: default avatarAdrian Huang (Lenovo) <adrianhuang0701@gmail.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6de1ef1c

include/linux/mm_types.h

+3 −3
Original line number Diff line number Diff line
@@ -1026,8 +1026,8 @@ struct mm_struct { 
					     * counters

					     */

		/*

		 * With some kernel config, the current mmap_lock's offset

		 * inside 'mm_struct' is at 0x120, which is very optimal, as

		 * Typically the current mmap_lock's offset is 56 bytes from

		 * the last cacheline boundary, which is very optimal, as

		 * its two hot fields 'count' and 'owner' sit in 2 different

		 * cachelines, and when mmap_lock is highly contended, both

		 * of the 2 fields will be accessed frequently, current layout