Commit ca7dc242 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm writecache: set a default MAX_WRITEBACK_JOBS 



dm-writecache has the capability to limit the number of writeback jobs
in progress. However, this feature was off by default. As such there
were some out-of-memory crashes observed when lowering the low
watermark while the cache is full.

This commit enables writeback limit by default. It is set to 256MiB or
1/16 of total system memory, whichever is smaller.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 11093e6f

drivers/md/dm-writecache.c

+1 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 


#define HIGH_WATERMARK			50

#define LOW_WATERMARK			45

#define MAX_WRITEBACK_JOBS		0

#define MAX_WRITEBACK_JOBS		min(0x10000000 / PAGE_SIZE, totalram_pages() / 16)

#define ENDIO_LATENCY			16

#define WRITEBACK_LATENCY		64

#define AUTOCOMMIT_BLOCKS_SSD		65536