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| author |   Mikulas Patocka <mpatocka@redhat.com> | 2021-07-27 09:42:21 -0400 |
|---|---|---|
| committer |   Mike Snitzer <snitzer@redhat.com> | 2021-08-10 13:27:49 -0400 |
| commit | e3a35d03407cb3ef9488835aa861e07b45638d0b (patch) | |
| tree | e008bfff0fa621966fd14270e7c083a87c8bd362 /Documentation/admin-guide/device-mapper/writecache.rst | |
| parent | dm writecache: report invalid return from writecache_map helpers (diff) | |
| download | linux-dev-e3a35d03407cb3ef9488835aa861e07b45638d0b.tar.xz linux-dev-e3a35d03407cb3ef9488835aa861e07b45638d0b.zip | |
dm writecache: add event counters
Add 10 counters for various events (hit, miss, etc) and export them in
the status line (accessed from userspace with "dmsetup status"). Also
add a message "clear_stats" that resets these counters.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'Documentation/admin-guide/device-mapper/writecache.rst')
| -rw-r--r-- | Documentation/admin-guide/device-mapper/writecache.rst | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index 65427d8dfca6..10429779a91a 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -78,13 +78,23 @@ Status: 2. the number of blocks 3. the number of free blocks 4. the number of blocks under writeback +5. the number of read requests +6. the number of read requests that hit the cache +7. the number of write requests +8. the number of write requests that hit uncommitted block +9. the number of write requests that hit committed block +10. the number of write requests that bypass the cache +11. the number of write requests that are allocated in the cache +12. the number of write requests that are blocked on the freelist +13. the number of flush requests +14. the number of discard requests Messages: flush - flush the cache device. The message returns successfully + Flush the cache device. The message returns successfully if the cache device was flushed without an error flush_on_suspend - flush the cache device on next suspend. Use this message + Flush the cache device on next suspend. Use this message when you are going to remove the cache device. The proper sequence for removing the cache device is: @@ -98,3 +108,5 @@ Messages: 6. the cache device is now inactive and it can be deleted cleaner See above "cleaner" constructor documentation. + clear_stats + Clear the statistics that are reported on the status line |