diff options
| author | Huang Ying <[email protected]> | 2017-02-22 15:45:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2017-02-22 16:41:30 -0800 |
| commit | ba81f83842549871cbd7226fc11530dc464500bb (patch) | |
| tree | 1722a6591e970b93efbbf51c39b6dd09f7832d6a /include/linux | |
| parent | 039939a65059852242c823ece685579370bc574f (diff) | |
mm/swap: skip readahead only when swap slot cache is enabled
Because during swap off, a swap entry may have swap_map[] ==
SWAP_HAS_CACHE (for example, just allocated). If we return NULL in
__read_swap_cache_async(), the swap off will abort. So when swap slot
cache is disabled, (for swap off), we will wait for page to be put into
swap cache in such race condition. This should not be a problem for swap
slot cache, because swap slot cache should be drained after clearing
swap_slot_cache_enabled.
[[email protected]: fix memory leak in __read_swap_cache_async()]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/5e2c5f6abe8e6eb0797408897b1bba80938e9b9d.1484082593.git.tim.c.chen@linux.intel.com
Signed-off-by: "Huang, Ying" <[email protected]>
Signed-off-by: Tim Chen <[email protected]>
Cc: Aaron Lu <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Jonathan Corbet <[email protected]> escreveu:
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/swap_slots.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/swap_slots.h b/include/linux/swap_slots.h index ba5623b27c60..6ef92d17633d 100644 --- a/include/linux/swap_slots.h +++ b/include/linux/swap_slots.h @@ -25,4 +25,6 @@ void reenable_swap_slots_cache_unlock(void); int enable_swap_slots_cache(void); int free_swap_slot(swp_entry_t entry); +extern bool swap_slot_cache_enabled; + #endif /* _LINUX_SWAP_SLOTS_H */ |