Author: pjd
Date: Fri Jan 20 22:04:59 2012
New Revision: 230397
URL: http://svn.freebsd.org/changeset/base/230397
Log:
By default turn off prefetch when listing snapshots.
In my tests it makes listing snapshots 19% faster with cold cache and
47% faster with warm cache.
MFC after: 1 week
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Fri Jan
20 21:49:56 2012 (r230396)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c Fri Jan
20 22:04:59 2012 (r230397)
@@ -81,6 +81,12 @@
CTASSERT(sizeof(zfs_cmd_t) < IOCPARM_MAX);
+static int snapshot_list_prefetch;
+SYSCTL_DECL(_vfs_zfs);
+TUNABLE_INT("vfs.zfs.snapshot_list_prefetch", &snapshot_list_prefetch);
+SYSCTL_INT(_vfs_zfs, OID_AUTO, snapshot_list_prefetch, CTLFLAG_RW,
+ &snapshot_list_prefetch, 0, "Prefetch data when listing snapshots");
+
static struct cdev *zfsdev;
extern void zfs_init(void);
@@ -2044,7 +2050,7 @@ zfs_ioc_snapshot_list_next(zfs_cmd_t *zc
int error;
top:
- if (zc->zc_cookie == 0)
+ if (snapshot_list_prefetch && zc->zc_cookie == 0)
(void) dmu_objset_find(zc->zc_name, dmu_objset_prefetch,
NULL, DS_FIND_SNAPSHOTS);
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
