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authorHugh Dickins <hughd@google.com>2014-07-02 18:22:38 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-07-03 12:21:54 -0400
commit66d2f4d28cd030220e7ea2a628993fcabcb956d1 (patch)
tree5aaf41f53d21b5c15f7f778f0c8735a0dbbf1a81 /mm
parentd18bbc215f81710e1eab7120becafa910554d68d (diff)
shmem: fix init_page_accessed use to stop !PageLRU bug
Under shmem swapping load, I sometimes hit the VM_BUG_ON_PAGE(!PageLRU) in isolate_lru_pages() at mm/vmscan.c:1281! Commit 2457aec63745 ("mm: non-atomically mark page accessed during page cache allocation where possible") looks like interrupted work-in-progress. mm/filemap.c's call to init_page_accessed() is fine, but not mm/shmem.c's - shmem_write_begin() is clearly wrong to use it after shmem_getpage(), when the page is always visible in radix_tree, and often already on LRU. Revert change to shmem_write_begin(), and use init_page_accessed() or mark_page_accessed() appropriately for SGP_WRITE in shmem_getpage_gfp(). SGP_WRITE also covers shmem_symlink(), which did not mark_page_accessed() before; but since many other filesystems use [__]page_symlink(), which did and does mark the page accessed, consider this as rectifying an oversight. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Prabhakar Lad <prabhakar.csengg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/shmem.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 8f419cff9e34..1140f49b6ded 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1029,6 +1029,9 @@ repeat:
1029 goto failed; 1029 goto failed;
1030 } 1030 }
1031 1031
1032 if (page && sgp == SGP_WRITE)
1033 mark_page_accessed(page);
1034
1032 /* fallocated page? */ 1035 /* fallocated page? */
1033 if (page && !PageUptodate(page)) { 1036 if (page && !PageUptodate(page)) {
1034 if (sgp != SGP_READ) 1037 if (sgp != SGP_READ)
@@ -1110,6 +1113,9 @@ repeat:
1110 shmem_recalc_inode(inode); 1113 shmem_recalc_inode(inode);
1111 spin_unlock(&info->lock); 1114 spin_unlock(&info->lock);
1112 1115
1116 if (sgp == SGP_WRITE)
1117 mark_page_accessed(page);
1118
1113 delete_from_swap_cache(page); 1119 delete_from_swap_cache(page);
1114 set_page_dirty(page); 1120 set_page_dirty(page);
1115 swap_free(swap); 1121 swap_free(swap);
@@ -1136,6 +1142,9 @@ repeat:
1136 1142
1137 __SetPageSwapBacked(page); 1143 __SetPageSwapBacked(page);
1138 __set_page_locked(page); 1144 __set_page_locked(page);
1145 if (sgp == SGP_WRITE)
1146 init_page_accessed(page);
1147
1139 error = mem_cgroup_charge_file(page, current->mm, 1148 error = mem_cgroup_charge_file(page, current->mm,
1140 gfp & GFP_RECLAIM_MASK); 1149 gfp & GFP_RECLAIM_MASK);
1141 if (error) 1150 if (error)
@@ -1412,13 +1421,9 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
1412 loff_t pos, unsigned len, unsigned flags, 1421 loff_t pos, unsigned len, unsigned flags,
1413 struct page **pagep, void **fsdata) 1422 struct page **pagep, void **fsdata)
1414{ 1423{
1415 int ret;
1416 struct inode *inode = mapping->host; 1424 struct inode *inode = mapping->host;
1417 pgoff_t index = pos >> PAGE_CACHE_SHIFT; 1425 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1418 ret = shmem_getpage(inode, index, pagep, SGP_WRITE, NULL); 1426 return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL);
1419 if (ret == 0 && *pagep)
1420 init_page_accessed(*pagep);
1421 return ret;
1422} 1427}
1423 1428
1424static int 1429static int