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authorDarrick J. Wong <darrick.wong@oracle.com>2019-02-07 19:37:16 +0100
committerDarrick J. Wong <darrick.wong@oracle.com>2019-02-12 01:07:01 +0100
commit9b2471797942a5947664818cfe2c6de93b43f37a (patch)
tree86d0012e44bc4595f08bdea44f599c156145cf27 /fs/xfs/xfs_trace.h
parentxfs: add tracepoints for high level iunlink operations (diff)
downloadlinux-9b2471797942a5947664818cfe2c6de93b43f37a.tar.xz
linux-9b2471797942a5947664818cfe2c6de93b43f37a.zip
xfs: cache unlinked pointers in an rhashtable
Use a rhashtable to cache the unlinked list incore. This should speed up unlinked processing considerably when there are a lot of inodes on the unlinked list because iunlink_remove no longer has to traverse an entire bucket list to find which inode points to the one being removed. The incore list structure records "X.next_unlinked = Y" relations, with the rhashtable using Y to index the records. This makes finding the inode X that points to a inode Y very quick. If our cache fails to find anything we can always fall back on the old method. FWIW this drastically reduces the amount of time it takes to remove inodes from the unlinked list. I wrote a program to open a lot of O_TMPFILE files and then close them in the same order, which takes a very long time if we have to traverse the unlinked lists. With the ptach, I see: + /d/t/tmpfile/tmpfile Opened 193531 files in 6.33s. Closed 193531 files in 5.86s real 0m12.192s user 0m0.064s sys 0m11.619s + cd / + umount /mnt real 0m0.050s user 0m0.004s sys 0m0.030s And without the patch: + /d/t/tmpfile/tmpfile Opened 193588 files in 6.35s. Closed 193588 files in 751.61s real 12m38.853s user 0m0.084s sys 12m34.470s + cd / + umount /mnt real 0m0.086s user 0m0.000s sys 0m0.060s Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
Diffstat (limited to '')
-rw-r--r--fs/xfs/xfs_trace.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index a6e384a642b1..c83ce022a355 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3447,6 +3447,7 @@ DEFINE_EVENT(xfs_ag_inode_class, name, \
TP_ARGS(ip))
DEFINE_AGINODE_EVENT(xfs_iunlink);
DEFINE_AGINODE_EVENT(xfs_iunlink_remove);
+DEFINE_AG_EVENT(xfs_iunlink_map_prev_fallback);
#endif /* _TRACE_XFS_H */