path: root/Documentation
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authorMariusz Dabrowski <mariusz.dabrowski@intel.com>2019-02-18 15:04:09 +0100
committerSong Liu <songliubraving@fb.com>2019-03-12 10:15:18 -0700
commita596d08677320925b69e70c0fdc4c0f59384a65e (patch)
tree7ba718e75decf5f3c210a30386229a410c7b1829 /Documentation
parent9205e44916b2ca2e959be4210133292a19e79b0d (diff)
raid5: set write hint for PPL
When the Partial Parity Log is enabled, circular buffer is used to store PPL data. Each write to RAID device causes overwrite of data in this buffer so some write_hint can be set to those request to help drives handle garbage collection. This patch adds new sysfs attribute which can be used to specify which write_hint should be assigned to PPL. Acked-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@intel.com> Signed-off-by: Song Liu <songliubraving@fb.com>
Diffstat (limited to 'Documentation')
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/admin-guide/md.rst b/Documentation/admin-guide/md.rst
index 84de718f24a4..3c51084ffd37 100644
--- a/Documentation/admin-guide/md.rst
+++ b/Documentation/admin-guide/md.rst
@@ -756,3 +756,6 @@ These currently include:
The cache mode for raid5. raid5 could include an extra disk for
caching. The mode can be "write-throuth" and "write-back". The
default is "write-through".
+ ppl_write_hint
+ NVMe stream ID to be set for each PPL write request.