Commit 2c7e93e3 authored Jul 13, 2022 by Mikulas Patocka Committed by Greg Kroah-Hartman Aug 25, 2022

dm writecache: set a default MAX_WRITEBACK_JOBS



commit ca7dc242e358e46d963b32f9d9dd829785a9e957 upstream.

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: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 05cef099

drivers/md/dm-writecache.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -20,7 +20,7 @@

		#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