+ mm-readahead-limit-page-cache-size-in-page_cache_ra_order.patch added to mm-unstable branch

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: mm/readahead: limit page cache size in page_cache_ra_order()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-readahead-limit-page-cache-size-in-page_cache_ra_order.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-readahead-limit-page-cache-size-in-page_cache_ra_order.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Gavin Shan <gshan@xxxxxxxxxx>
Subject: mm/readahead: limit page cache size in page_cache_ra_order()
Date: Tue, 25 Jun 2024 19:06:45 +1000

In page_cache_ra_order(), the maximal order of the page cache to be
allocated shouldn't be larger than MAX_PAGECACHE_ORDER.  Otherwise, it's
possible the large page cache can't be supported by xarray when the
corresponding xarray entry is split.

For example, HPAGE_PMD_ORDER is 13 on ARM64 when the base page size is
64KB.  The PMD-sized page cache can't be supported by xarray.

Link: https://lkml.kernel.org/r/20240625090646.1194644-4-gshan@xxxxxxxxxx
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Zhenyu Zhang <zhenyzha@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/readahead.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/mm/readahead.c~mm-readahead-limit-page-cache-size-in-page_cache_ra_order
+++ a/mm/readahead.c
@@ -449,11 +449,11 @@ void page_cache_ra_order(struct readahea
 
 	limit = min(limit, index + ra->size - 1);
 
-	if (new_order < MAX_PAGECACHE_ORDER) {
+	if (new_order < MAX_PAGECACHE_ORDER)
 		new_order += 2;
-		new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order);
-		new_order = min_t(unsigned int, new_order, ilog2(ra->size));
-	}
+
+	new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order);
+	new_order = min_t(unsigned int, new_order, ilog2(ra->size));
 
 	/* See comment in page_cache_ra_unbounded() */
 	nofs = memalloc_nofs_save();
_

Patches currently in -mm which might be from gshan@xxxxxxxxxx are

mm-filemap-make-max_pagecache_order-acceptable-to-xarray.patch
mm-filemap-skip-to-allocate-pmd-sized-folios-if-needed.patch
mm-readahead-limit-page-cache-size-in-page_cache_ra_order.patch
mm-shmem-disable-pmd-sized-page-cache-if-needed.patch





[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux