Author: markj
Date: Thu Nov 30 20:36:29 2017
New Revision: 326409
URL: https://svnweb.freebsd.org/changeset/base/326409
Log:
Update gmirror metadata less frequently when synchronizing.
We periodically record synchronization progress in the metadata
block of the disk being synchronized; this allows an interrupted
synchronization to be resumed. However, the frequency of these
updates heavily pessimized synchronization time on some media. This
change modifies gmirror to update metadata based on a time period,
and adds a sysctl to control that period. The default value results
in a much lower update frequency and increases the completion time
for an interrupted rebuild only marginally.
Reported by: Andre Albsmeier <an...@fbsd.e4m.org>
MFC after: 3 weeks
Modified:
head/sys/geom/mirror/g_mirror.c
head/sys/geom/mirror/g_mirror.h
Modified: head/sys/geom/mirror/g_mirror.c
==============================================================================
--- head/sys/geom/mirror/g_mirror.c Thu Nov 30 20:33:45 2017
(r326408)
+++ head/sys/geom/mirror/g_mirror.c Thu Nov 30 20:36:29 2017
(r326409)
@@ -71,6 +71,10 @@ SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on
static u_int g_mirror_syncreqs = 2;
SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
&g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
+static u_int g_mirror_sync_period = 5;
+SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_update_period, CTLFLAG_RWTUN,
+ &g_mirror_sync_period, 0,
+ "Metadata update period during synchroniztion, in seconds");
#define MSLEEP(ident, mtx, priority, wmesg, timeout) do {
\
G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident)); \
@@ -465,6 +469,7 @@ g_mirror_init_disk(struct g_mirror_softc *sc, struct g
disk->d_sync.ds_consumer = NULL;
disk->d_sync.ds_offset = md->md_sync_offset;
disk->d_sync.ds_offset_done = md->md_sync_offset;
+ disk->d_sync.ds_update_ts = time_uptime;
disk->d_genid = md->md_genid;
disk->d_sync.ds_syncid = md->md_syncid;
if (errorp != NULL)
@@ -1459,10 +1464,11 @@ g_mirror_sync_request(struct bio *bp)
if (bp != NULL && bp->bio_offset < offset)
offset = bp->bio_offset;
}
- if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
- /* Update offset_done on every 100 blocks. */
+ if (g_mirror_sync_period > 0 &&
+ time_uptime - sync->ds_update_ts > g_mirror_sync_period) {
sync->ds_offset_done = offset;
g_mirror_update_metadata(disk);
+ sync->ds_update_ts = time_uptime;
}
return;
}
Modified: head/sys/geom/mirror/g_mirror.h
==============================================================================
--- head/sys/geom/mirror/g_mirror.h Thu Nov 30 20:33:45 2017
(r326408)
+++ head/sys/geom/mirror/g_mirror.h Thu Nov 30 20:36:29 2017
(r326409)
@@ -110,6 +110,7 @@ struct g_mirror_disk_sync {
off_t ds_offset; /* Offset of next request to send. */
off_t ds_offset_done; /* Offset of already synchronized
region. */
+ time_t ds_update_ts; /* Time of last metadata update. */
u_int ds_syncid; /* Disk's synchronization ID. */
u_int ds_inflight; /* Number of in-flight sync requests. */
struct bio **ds_bios; /* BIOs for synchronization I/O. */
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