From 5c0de3d72f8c05678ed769bea24e98128f7ab570 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 28 Jun 2021 09:59:37 -0400 Subject: dm writecache: make writeback pause configurable Commit 95b88f4d71cb953e02206be3c757083601391a0f ("dm writecache: pause writeback if cache full and origin being written directly") introduced a code that pauses cache flushing if we are issuing writes directly to the origin. Improve that initial commit by making the timeout code configurable (via the option "pause_writeback"). Also change the default from 1s to 3s because it performed better. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- Documentation/admin-guide/device-mapper/writecache.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'Documentation/admin-guide') diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index 977f82b5a811..65427d8dfca6 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -12,7 +12,6 @@ first sector should contain valid superblock from previous invocation. Constructor parameters: 1. type of the cache device - "p" or "s" - - p - persistent memory - s - SSD 2. the underlying device that will be cached @@ -21,7 +20,6 @@ Constructor parameters: size) 5. the number of optional parameters (the parameters with an argument count as two) - start_sector n (default: 0) offset from the start of cache device in 512-byte sectors high_watermark n (default: 50) @@ -71,6 +69,9 @@ Constructor parameters: metadata_only only metadata is promoted to the cache. This option improves performance for heavier REQ_META workloads. + pause_writeback n (default: 3000) + pause writeback if there was some write I/O redirected to + the origin volume in the last n milliseconds Status: 1. error indicator - 0 if there was no error, otherwise error number -- cgit v1.2.3