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| author | Yang Shi <yang.shi@linux.alibaba.com> | 2019-12-01 04:58:07 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-01 23:59:10 +0300 |
| commit | 4afab1cd256e425803374b58702ea86a05b0acf9 (patch) | |
| tree | 34e8c9bf32216e98ecc336c2fcb420a3966aacb7 | |
| parent | 26083eb6b15448e7ec5182e33f9b1ba7ebce3a62 (diff) | |
| download | linux-4afab1cd256e425803374b58702ea86a05b0acf9.tar.xz | |
mm: shmem: use proper gfp flags for shmem_writepage()
The shmem_writepage() uses GFP_ATOMIC to allocate swap cache. GFP_ATOMIC
used to mean __GFP_HIGH, but now it means __GFP_HIGH | __GFP_ATOMIC |
__GFP_KSWAPD_RECLAIM. However, shmem_writepage() should write out to swap
only in response to memory pressure, so __GFP_KSWAPD_RECLAIM looks useless
since the caller may be kswapd itself or in direct reclaim already.
In addition, XArray node allocations from PF_MEMALLOC contexts could
completely exhaust the page allocator, __GFP_NOMEMALLOC stops emergency
reserves from being allocated.
Here just copy the gfp flags used by add_to_swap().
Hugh:
"a cleanup to make the two calls look the same when they don't need to
be different (whereas the call from __read_swap_cache_async() rightly
uses a lower priority gfp)".
Link: http://lkml.kernel.org/r/1572991351-86061-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/shmem.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 6e4e742db5c2..3c336b02cf08 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1369,7 +1369,8 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) if (list_empty(&info->swaplist)) list_add(&info->swaplist, &shmem_swaplist); - if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { + if (add_to_swap_cache(page, swap, + __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN) == 0) { spin_lock_irq(&info->lock); shmem_recalc_inode(inode); info->swapped++; |