[LU-12394] lctl get_param llite.lfs*.extents_stats only displays first two buckets

Related — Thu, 12 Sep 2019 04:17:48 +0000

ll_extent_stats is broken on recent versions, displaying on the 0-4K and 4K - 8K buckets:

lctl get_param llite.*.extents_stats
llite.[...].extents_stats=
snapshot_time:         1559766954.651554186 (secs.nsecs)
                               read       |                write
      extents            calls    % cum%  |          calls    % cum%
   0K -    4K :              0    0    0  |              0    0    0
   4K -    8K :              0    0    0  |         207590  100  100

This was broken in:

commit adb5aca3d67380078c4bd35c74651a7b9f848f4d
Author: James Simmons <uja.ornl@yahoo.com>
Date: Sat Oct 13 15:24:46 2018 -0400

LU-8066 llite: Move all remaining procfs entries to debugfs

This moves all remaining procfs handling in llite layer to debugfs.

This is a modified version of

Linux-commit : ae7c0f4833a65b7648cceaf1a60503a89e057f0f

Change-Id: Id5c411d21a660a17a015ca9976b857e6b088c28a
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/32517
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Ben Evans <bevans@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

By this change:

-        for(i = 0; (count >= (1 << LL_HIST_START << i)) &&
+       for(i = 0; (count >= BIT(LL_HIST_START << i)) &&

BIT(LL_HIST_START << i) is not actually the same as 1 << LL_HIST_START << i due to operation ordering details.

BIT(LL_HIST_START + i) gives the desired behavior.

Whamcloud Community JIRA

[LU-12394] lctl get_param llite.lfs*.extents_stats only displays first two buckets