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| author | Michal Hocko <mhocko@suse.com> | 2016-07-27 01:24:53 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 02:19:19 +0300 |
| commit | 8a5c743e308dd2b90ad10d1faaa7a1b09173a132 (patch) | |
| tree | ba679ecefc77b4a80bd35b00e55ddc1457b14e07 /fs/orangefs/inode.c | |
| parent | e5e3f4c4f0e95ecbad2f8d2f4f6a29bb8a90226b (diff) | |
| download | linux-8a5c743e308dd2b90ad10d1faaa7a1b09173a132.tar.xz | |
mm, memcg: use consistent gfp flags during readahead
Vladimir has noticed that we might declare memcg oom even during
readahead because read_pages only uses GFP_KERNEL (with mapping_gfp
restriction) while __do_page_cache_readahead uses
page_cache_alloc_readahead which adds __GFP_NORETRY to prevent from
OOMs. This gfp mask discrepancy is really unfortunate and easily
fixable. Drop page_cache_alloc_readahead() which only has one user and
outsource the gfp_mask logic into readahead_gfp_mask and propagate this
mask from __do_page_cache_readahead down to read_pages.
This alone would have only very limited impact as most filesystems are
implementing ->readpages and the common implementation mpage_readpages
does GFP_KERNEL (with mapping_gfp restriction) again. We can tell it to
use readahead_gfp_mask instead as this function is called only during
readahead as well. The same applies to read_cache_pages.
ext4 has its own ext4_mpage_readpages but the path which has pages !=
NULL can use the same gfp mask. Btrfs, cifs, f2fs and orangefs are
doing a very similar pattern to mpage_readpages so the same can be
applied to them as well.
[akpm@linux-foundation.org: coding-style fixes]
[mhocko@suse.com: restrict gfp mask in mpage_alloc]
Link: http://lkml.kernel.org/r/20160610074223.GC32285@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1465301556-26431-1-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Chris Mason <clm@fb.com>
Cc: Steve French <sfrench@samba.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Changman Lee <cm224.lee@samsung.com>
Cc: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/orangefs/inode.c')
| -rw-r--r-- | fs/orangefs/inode.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c index 85640e955cde..06a8da75651d 100644 --- a/fs/orangefs/inode.c +++ b/fs/orangefs/inode.c @@ -80,7 +80,7 @@ static int orangefs_readpages(struct file *file, if (!add_to_page_cache(page, mapping, page->index, - GFP_KERNEL)) { + readahead_gfp_mask(mapping))) { ret = read_one_page(page); gossip_debug(GOSSIP_INODE_DEBUG, "failure adding page to cache, read_one_page returned: %d\n", |