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authorAlexander Motin <[email protected]>2020-10-30 11:57:54 -0400
committerGitHub <[email protected]>2020-10-30 08:57:54 -0700
commit1199c3e8fb9006f28e11c747101ba770cc0bf743 (patch)
treec7519903ec9eb15045d5e4e4d4d3e83732894ff4 /module
parent76d04993a60fcd30bbb815cfa7f716cbebcdfcbd (diff)
Yield periodically when rebuilding L2ARC
L2ARC devices of several terabytes filled with 4KB blocks may take 15 minutes to rebuild. Due to the way L2ARC log reading is implemented it is quite likely that for all that time rebuild thread will never sleep. At least on FreeBSD kernel threads have absolute priority and can not be preempted by threads with lower priorities. If some thread is also bound to that specific CPU it may not get any CPU time for all the 15 minutes. Reviewed-by: Cedric Berger <[email protected]> Reviewed-by: Ryan Moeller <[email protected]> Reviewed-by: George Amanakis <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Alexander Motin <[email protected]> Closes #11116
Diffstat (limited to 'module')
-rw-r--r--module/zfs/arc.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 1e3d47693..72a71bafd 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -9893,6 +9893,7 @@ l2arc_rebuild(l2arc_dev_t *dev)
!dev->l2ad_first)
goto out;
+ cond_resched();
for (;;) {
mutex_enter(&l2arc_rebuild_thr_lock);
if (dev->l2ad_rebuild_cancel) {