diff options
author | Justin Gottula <[email protected]> | 2019-03-12 15:03:59 -0700 |
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committer | Brian Behlendorf <[email protected]> | 2019-03-12 15:03:59 -0700 |
commit | cffa8372f42be4b37931d3cd24b01e837aa123b6 (patch) | |
tree | 6f5368e71302bfba282706bd52309244f57041db /module | |
parent | 4c0883fb4af0d5565459099b98fcf90ecbfa1ca1 (diff) |
Fix most zfs_arc_* mod params not actually being modifiable at runtime
Most of the zfs_arc_* module parameters do not have their values used by
the ARC code directly. Instead, there is a function, arc_tuning_update,
which is called during module initialization and periodically
thereafter, whose job is to fetch the module parameter values, clamp/
limit them appropriately, and then assign those values to a separate set
of internal variables that are actually referenced by the ARC code.
Commit 3ec34e55 featured an overhaul of arc_reclaim_thread, which is the
former location where the post-init-time calls to arc_tuning_update
would occur. The rework split the work previously done by the
arc_reclaim_thread into a pair of replacement threads; and
unfortunately, the call to arc_tuning_update fell through the cracks and
was lost in the reorganization.
This meant that changing almost any ARC-related zfs module parameter via
/sys/module/zfs/parameters/ would result in the module parameter value
itself appearing to change; however the modification would not actually
propagate to the ARC code and have any real effect.
This commit reinstates the post-init-time call to arc_tuning_update. It
is now called during arc_adjust_cb_check; this should be equivalent to
its former call location in arc_reclaim_thread.
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Tony Hutter <[email protected]>
Signed-off-by: Justin Gottula <[email protected]>
Closes #8405
Closes #8463
Diffstat (limited to 'module')
-rw-r--r-- | module/zfs/arc.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/module/zfs/arc.c b/module/zfs/arc.c index 9072b6582..637333ed2 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -5077,6 +5077,14 @@ static boolean_t arc_adjust_cb_check(void *arg, zthr_t *zthr) { /* + * This is necessary so that any changes which may have been made to + * many of the zfs_arc_* module parameters will be propagated to + * their actual internal variable counterparts. Without this, + * changing those module params at runtime would have no effect. + */ + arc_tuning_update(); + + /* * This is necessary in order to keep the kstat information * up to date for tools that display kstat data such as the * mdb ::arc dcmd and the Linux crash utility. These tools |