Commit df0ad057 authored by Rik van Riel's avatar Rik van Riel Committed by Kefeng Wang
Browse files

mm: align larger anonymous mappings on THP boundaries 

mainline inclusion
from mainline-v6.7
commit efa7df3e3bb5da8e6abbe37727417f32a37fba47
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9H84X
CVE: NA

-------------------------------------------------

Align larger anonymous memory mappings on THP boundaries by going through
thp_get_unmapped_area if THPs are enabled for the current process.

With this patch, larger anonymous mappings are now THP aligned.  When a
malloc library allocates a 2MB or larger arena, that arena can now be
mapped with THPs right from the start, which can result in better TLB hit
rates and execution time.

Link: https://lkml.kernel.org/r/20220809142457.4751229f@imladris.surriel.com
Link: https://lkml.kernel.org/r/20231214223423.1133074-1-yang@os.amperecomputing.com


Signed-off-by: default avatarRik van Riel <riel@surriel.com>
Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christopher Lameter <cl@linux.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
(cherry picked from commit efa7df3e3bb5da8e6abbe37727417f32a37fba47)
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
parent 399c6fe8

mm/mmap.c

+3 −0
Original line number Diff line number Diff line
@@ -1850,6 +1850,9 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, 
		 */

		pgoff = 0;

		get_area = shmem_get_unmapped_area;

	} else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {

		/* Ensures that larger anonymous mappings are THP aligned. */

		get_area = thp_get_unmapped_area;

	}



	addr = get_area(file, addr, len, pgoff, flags);