summaryrefslogtreecommitdiff
path: root/fs/ext4/inode.c
diff options
context:
space:
mode:
authorTheodore Ts'o <tytso@mit.edu>2019-11-28 22:26:51 -0500
committerTheodore Ts'o <tytso@mit.edu>2020-01-17 16:24:25 -0500
commitd4c5e960bf202d99ec9a6922ad387eafb798b848 (patch)
treeee055127be4ebb1c9eccf1cee15185327255d6d2 /fs/ext4/inode.c
parent8cd115bdda17751ee2adab614a80df72228b3809 (diff)
ext4: avoid fetching btime in ext4_getattr() unless requested
Linus observed that an allmodconfig build which does a lot of stat(2) calls that ext4_getattr() was a noticeable (1%) amount of CPU time, due to the cache line for i_extra_isize getting pulled in. Since the normal stat system call doesn't return btime, it's a complete waste. So only calculate btime when it is explicitly requested. [ Fixed to check against request_mask instead of query_flags. ] Link: https://lore.kernel.org/r/CAHk-=wivmk_j6KbTX+Er64mLrG8abXZo0M10PNdAnHc8fWXfsQ@mail.gmail.com Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r--fs/ext4/inode.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d035acab5b2a..9100460d92e5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5399,7 +5399,8 @@ int ext4_getattr(const struct path *path, struct kstat *stat,
struct ext4_inode_info *ei = EXT4_I(inode);
unsigned int flags;
- if (EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) {
+ if ((request_mask & STATX_BTIME) &&
+ EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) {
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = ei->i_crtime.tv_sec;
stat->btime.tv_nsec = ei->i_crtime.tv_nsec;