| Message ID | 170086926609.2770816.18279950636495716216.stgit@frogsfrogsfrogs (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | xfs: prepare repair for bulk loading | expand |
On Fri, Nov 24, 2023 at 03:49:15PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <djwong@kernel.org> > > Add some debug knobs so that we can control the leaf and node block > slack when rebuilding btrees. Maybe expand a bit on what these "debug knows" are useful for and how they work?
On Fri, Nov 24, 2023 at 09:50:23PM -0800, Christoph Hellwig wrote: > On Fri, Nov 24, 2023 at 03:49:15PM -0800, Darrick J. Wong wrote: > > From: Darrick J. Wong <djwong@kernel.org> > > > > Add some debug knobs so that we can control the leaf and node block > > slack when rebuilding btrees. > > Maybe expand a bit on what these "debug knows" are useful for and how > they work? They're not generally useful for users, obviously. For developers, it might be useful to construct btrees of various heights by crafting a filesystem with a certain number of records and then using repair+knobs to rebuild the index with a certain shape. Practically speaking, you'd only ever do that for extreme stress testing. --D
On Mon, Nov 27, 2023 at 05:44:37PM -0800, Darrick J. Wong wrote: > They're not generally useful for users, obviously. For developers, it > might be useful to construct btrees of various heights by crafting a > filesystem with a certain number of records and then using repair+knobs > to rebuild the index with a certain shape. > > Practically speaking, you'd only ever do that for extreme stress > testing. Please add this to the commit message.
On Mon, Nov 27, 2023 at 09:42:37PM -0800, Christoph Hellwig wrote: > On Mon, Nov 27, 2023 at 05:44:37PM -0800, Darrick J. Wong wrote: > > They're not generally useful for users, obviously. For developers, it > > might be useful to construct btrees of various heights by crafting a > > filesystem with a certain number of records and then using repair+knobs > > to rebuild the index with a certain shape. > > > > Practically speaking, you'd only ever do that for extreme stress > > testing. > > Please add this to the commit message. Done. --D > >
diff --git a/fs/xfs/scrub/newbt.c b/fs/xfs/scrub/newbt.c index 2932fd317ab23..2c388c647d37f 100644 --- a/fs/xfs/scrub/newbt.c +++ b/fs/xfs/scrub/newbt.c @@ -47,9 +47,13 @@ xrep_newbt_estimate_slack( uint64_t free; uint64_t sz; - /* Let the btree code compute the default slack values. */ - bload->leaf_slack = -1; - bload->node_slack = -1; + /* + * The xfs_globals values are set to -1 (i.e. take the bload defaults) + * unless someone has set them otherwise, so we just pull the values + * here. + */ + bload->leaf_slack = xfs_globals.bload_leaf_slack; + bload->node_slack = xfs_globals.bload_node_slack; if (sc->ops->type == ST_PERAG) { free = sc->sa.pag->pagf_freeblks; diff --git a/fs/xfs/xfs_globals.c b/fs/xfs/xfs_globals.c index 9edc1f2bc9399..f18fec0adf666 100644 --- a/fs/xfs/xfs_globals.c +++ b/fs/xfs/xfs_globals.c @@ -44,4 +44,16 @@ struct xfs_globals xfs_globals = { .pwork_threads = -1, /* automatic thread detection */ .larp = false, /* log attribute replay */ #endif + + /* + * Leave this many record slots empty when bulk loading btrees. By + * default we load new btree leaf blocks 75% full. + */ + .bload_leaf_slack = -1, + + /* + * Leave this many key/ptr slots empty when bulk loading btrees. By + * default we load new btree node blocks 75% full. + */ + .bload_node_slack = -1, }; diff --git a/fs/xfs/xfs_sysctl.h b/fs/xfs/xfs_sysctl.h index f78ad6b10ea58..276696a07040c 100644 --- a/fs/xfs/xfs_sysctl.h +++ b/fs/xfs/xfs_sysctl.h @@ -85,6 +85,8 @@ struct xfs_globals { int pwork_threads; /* parallel workqueue threads */ bool larp; /* log attribute replay */ #endif + int bload_leaf_slack; /* btree bulk load leaf slack */ + int bload_node_slack; /* btree bulk load node slack */ int log_recovery_delay; /* log recovery delay (secs) */ int mount_delay; /* mount setup delay (secs) */ bool bug_on_assert; /* BUG() the kernel on assert failure */ diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c index a3c6b15487237..4eaa0507ec287 100644 --- a/fs/xfs/xfs_sysfs.c +++ b/fs/xfs/xfs_sysfs.c @@ -253,6 +253,58 @@ larp_show( XFS_SYSFS_ATTR_RW(larp); #endif /* DEBUG */ +STATIC ssize_t +bload_leaf_slack_store( + struct kobject *kobject, + const char *buf, + size_t count) +{ + int ret; + int val; + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + xfs_globals.bload_leaf_slack = val; + return count; +} + +STATIC ssize_t +bload_leaf_slack_show( + struct kobject *kobject, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.bload_leaf_slack); +} +XFS_SYSFS_ATTR_RW(bload_leaf_slack); + +STATIC ssize_t +bload_node_slack_store( + struct kobject *kobject, + const char *buf, + size_t count) +{ + int ret; + int val; + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + xfs_globals.bload_node_slack = val; + return count; +} + +STATIC ssize_t +bload_node_slack_show( + struct kobject *kobject, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.bload_node_slack); +} +XFS_SYSFS_ATTR_RW(bload_node_slack); + static struct attribute *xfs_dbg_attrs[] = { ATTR_LIST(bug_on_assert), ATTR_LIST(log_recovery_delay), @@ -262,6 +314,8 @@ static struct attribute *xfs_dbg_attrs[] = { ATTR_LIST(pwork_threads), ATTR_LIST(larp), #endif + ATTR_LIST(bload_leaf_slack), + ATTR_LIST(bload_node_slack), NULL, }; ATTRIBUTE_GROUPS(xfs_dbg);