c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-05-22 02:27:36 +03:00
Code Issues Packages Projects Releases Wiki Activity

Remove duplicate dbufs accounting

Browse Source 
Since AVL already has embedded element counter, use dn_dbufs_count
only for dbufs not counted there (bonus buffers) and just add them.
This removes two atomics per dbuf life cycle.

According to profiler it reduces time spent by dbuf_destroy() inside
bottlenecked dbuf_evict_thread() from 13.36% to 9.20% of the core.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #9949
This commit is contained in:
Alexander Motin
2020-02-13 14:20:42 -05:00
committed by GitHub
parent 610eec452d
commit 465e4e795e
3 changed files with 9 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/sys/dnode.h
+7
View File
@@ -372,6 +372,13 @@ struct dnode {
struct zfetch dn_zfetch;
};
/*
* Since AVL already has embedded element counter, use dn_dbufs_count
* only for dbufs not counted there (bonus buffers) and just add them.
*/
#define DN_DBUFS_COUNT(dn) ((dn)->dn_dbufs_count + \
avl_numnodes(&(dn)->dn_dbufs))
/*
* We use this (otherwise unused) bit to indicate if the value of
* dn_next_maxblkid[txgoff] is valid to use in dnode_sync().