mirror of https://gitee.com/openkylin/linux.git
8a5c743e30
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> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| asn1.c | ||
| cache.c | ||
| cifs_debug.c | ||
| cifs_debug.h | ||
| cifs_dfs_ref.c | ||
| cifs_fs_sb.h | ||
| cifs_ioctl.h | ||
| cifs_spnego.c | ||
| cifs_spnego.h | ||
| cifs_unicode.c | ||
| cifs_unicode.h | ||
| cifs_uniupr.h | ||
| cifsacl.c | ||
| cifsacl.h | ||
| cifsencrypt.c | ||
| cifsfs.c | ||
| cifsfs.h | ||
| cifsglob.h | ||
| cifspdu.h | ||
| cifsproto.h | ||
| cifssmb.c | ||
| connect.c | ||
| dir.c | ||
| dns_resolve.c | ||
| dns_resolve.h | ||
| export.c | ||
| file.c | ||
| fscache.c | ||
| fscache.h | ||
| inode.c | ||
| ioctl.c | ||
| link.c | ||
| misc.c | ||
| netmisc.c | ||
| nterr.c | ||
| nterr.h | ||
| ntlmssp.h | ||
| readdir.c | ||
| rfc1002pdu.h | ||
| sess.c | ||
| smb1ops.c | ||
| smb2file.c | ||
| smb2glob.h | ||
| smb2inode.c | ||
| smb2maperror.c | ||
| smb2misc.c | ||
| smb2ops.c | ||
| smb2pdu.c | ||
| smb2pdu.h | ||
| smb2proto.h | ||
| smb2status.h | ||
| smb2transport.c | ||
| smbencrypt.c | ||
| smberr.h | ||
| smbfsctl.h | ||
| transport.c | ||
| winucase.c | ||
| xattr.c | ||