Differences

This shows you the differences between two versions of the page.

--- andriygapon:avgzfsproblemlist [2013/07/25 08:38] – AndriyGapon
+++ andriygapon:avgzfsproblemlist [2018/03/12 02:55] (current) – add to CategoryZfs. MarkLinimon
@@ Line 1: / Line 1: @@
 === List of interesting issues with ZFS (in no particular order) ===
-== Priorities of ZFS worker threads ==
+== LOR between page "lock" and z_teardown_lock ==
-Compression/decompression/etc potentially takes a lot of CPU.
+One thread could have a page busy and then stumble into z_teardown_lock while trying to write out the page.
+Another thread could be doing a rollback, thus it would hold z_teardown_lock and then try to discard potentially stale pages of a vnode.
-See a complaint here: http://thread.gmane.org/gmane.os.freebsd.stable/85097/focus=85100
+For that it would need to wait for each page to get "unbusied".
-One quick fix is to use PUSER priority as done in GELI driver.
-More investigation is needed.
 == Memory allocations in ARC ==
@@ Line 91: / Line 88: @@
 This needs support for "hierarchical" dumping in %%FreeBSD%%.
 Dump should call into ZVOL code and the ZVOL code should be able to do dumping onto geoms of vdev and all the way down to real disk drivers.
+== Priorities of ZFS worker threads ==
+Compression/decompression/etc potentially takes a lot of CPU.
+See a complaint here: http://thread.gmane.org/gmane.os.freebsd.stable/85097/focus=85100
+One quick fix is to use PUSER priority as done in GELI driver.
+More investigation is needed.
+----
+{{tag>Zfs}}