From 7d6f07d2c5ad9fce298889eeed317d512a2df8cd Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 6 Aug 2021 11:05:40 -0700 Subject: [PATCH] xfs: queue inactivation immediately when free space is tight Now that we have made the inactivation of unlinked inodes a background task to increase the throughput of file deletions, we need to be a little more careful about how long of a delay we can tolerate. On a mostly empty filesystem, the risk of the allocator making poor decisions due to fragmentation of the free space on account a lengthy delay in background updates is minimal because there's plenty of space. However, if free space is tight, we want to deallocate unlinked inodes as quickly as possible to avoid fallocate ENOSPC and to give the allocator the best shot at optimal allocations for new writes. Therefore, queue the percpu worker immediately if the filesystem is more than 95% full. This follows the same principle that XFS becomes less aggressive about speculative allocations and lazy cleanup (and more precise about accounting) when nearing full. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- fs/xfs/xfs_icache.c | 6 ++++++ fs/xfs/xfs_mount.c | 8 -------- fs/xfs/xfs_mount.h | 9 +++++++++ 3 files changed, 15 insertions(+), 8 deletions(-) diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 7d93edb..8b2ac969 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -1920,6 +1920,7 @@ xfs_inodegc_start( * Schedule the inactivation worker when: * * - We've accumulated more than one inode cluster buffer's worth of inodes. + * - There is less than 5% free space left. */ static inline bool xfs_inodegc_want_queue_work( @@ -1931,6 +1932,11 @@ xfs_inodegc_want_queue_work( if (items > mp->m_ino_geo.inodes_per_cluster) return true; + if (__percpu_counter_compare(&mp->m_fdblocks, + mp->m_low_space[XFS_LOWSP_5_PCNT], + XFS_FDBLOCKS_BATCH) < 0) + return true; + return false; } diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index 1f7e9a6..5fe6f1d 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -1077,14 +1077,6 @@ xfs_fs_writable( return true; } -/* - * Deltas for the block count can vary from 1 to very large, but lock contention - * only occurs on frequent small block count updates such as in the delayed - * allocation path for buffered writes (page a time updates). Hence we set - * a large batch count (1024) to minimise global counter updates except when - * we get near to ENOSPC and we have to be very accurate with our updates. - */ -#define XFS_FDBLOCKS_BATCH 1024 int xfs_mod_fdblocks( struct xfs_mount *mp, diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index e6f8675e..60468a2 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -348,6 +348,15 @@ extern uint64_t xfs_default_resblks(xfs_mount_t *mp); extern int xfs_mountfs(xfs_mount_t *mp); extern void xfs_unmountfs(xfs_mount_t *); +/* + * Deltas for the block count can vary from 1 to very large, but lock contention + * only occurs on frequent small block count updates such as in the delayed + * allocation path for buffered writes (page a time updates). Hence we set + * a large batch count (1024) to minimise global counter updates except when + * we get near to ENOSPC and we have to be very accurate with our updates. + */ +#define XFS_FDBLOCKS_BATCH 1024 + extern int xfs_mod_fdblocks(struct xfs_mount *mp, int64_t delta, bool reserved); extern int xfs_mod_frextents(struct xfs_mount *mp, int64_t delta); -- 2.7.4