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| author | Sergey Senozhatsky <senozhatsky@chromium.org> | 2022-11-22 12:30:22 +0900 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-30 15:59:07 -0800 |
| commit | 8d9b63708ddd1ac51e0260c7b8f641daf01f4caf (patch) | |
| tree | 5b556095bef64db52c2a43904500cedf3e94153d /mm/zpool.c | |
| parent | 7ce5f7e16afa82d33dc47d633404b8b1142a5e44 (diff) | |
| download | lwn-8d9b63708ddd1ac51e0260c7b8f641daf01f4caf.tar.gz lwn-8d9b63708ddd1ac51e0260c7b8f641daf01f4caf.zip | |
zswap: do not allocate from atomic pool
zswap_frontswap_load() should be called from preemptible context (we even
call mutex_lock() there) and it does not look like we need to do
GFP_ATOMIC allocaion for temp buffer. The same applies to
zswap_writeback_entry().
Use GFP_KERNEL for temporary buffer allocation in both cases.
Link: https://lkml.kernel.org/r/Y3xCTr6ikbtcUr/y@google.com
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/zpool.c')
| -rw-r--r-- | mm/zpool.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/zpool.c b/mm/zpool.c index 68facc193496..f46c0d5e766c 100644 --- a/mm/zpool.c +++ b/mm/zpool.c @@ -387,6 +387,13 @@ bool zpool_evictable(struct zpool *zpool) * zpool_can_sleep_mapped - Test if zpool can sleep when do mapped. * @zpool: The zpool to test * + * Some allocators enter non-preemptible context in ->map() callback (e.g. + * disable pagefaults) and exit that context in ->unmap(), which limits what + * we can do with the mapped object. For instance, we cannot wait for + * asynchronous crypto API to decompress such an object or take mutexes + * since those will call into the scheduler. This function tells us whether + * we use such an allocator. + * * Returns: true if zpool can sleep; false otherwise. */ bool zpool_can_sleep_mapped(struct zpool *zpool) |