From 1e0cba17863a72714ee5764bfda25e877a534a5d Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 13 Jul 2022 07:09:04 -0400 Subject: [PATCH] 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: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-writecache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index d74c5a7a0ab49..d572135cd43fa 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -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 -- 2.39.5