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author | Eric Sandeen <sandeen@sandeen.net> | 2010-02-03 17:50:13 (GMT) |
---|---|---|
committer | Alex Elder <aelder@sgi.com> | 2010-03-01 22:33:41 (GMT) |
commit | a9cc799eca0c798ab5dd8648564fc2025bdd9bd2 (patch) | |
tree | 8776d8ba707dd7e87fd282335ef3ed66ba9973b4 /fs/xfs | |
parent | 398007f863a4af2b4a5a07219c5a617f1a098115 (diff) | |
download | linux-a9cc799eca0c798ab5dd8648564fc2025bdd9bd2.tar.xz |
xfs: increase readdir buffer size
While doing some testing of readdir perf a while back,
I noticed that the buffer size we're using internally is
smaller than what glibc gives us by default. Upping this
size helped a bit, and seems safe.
glibc's __alloc_dir() does:
const size_t default_allocation = (4 * BUFSIZ < sizeof (struct dirent64)
? sizeof (struct dirent64) : 4 * BUFSIZ);
const size_t small_allocation = (BUFSIZ < sizeof (struct dirent64)
? sizeof (struct dirent64) : BUFSIZ);
size_t allocation = default_allocation;
#ifdef _STATBUF_ST_BLKSIZE
if (statp != NULL && default_allocation < statp->st_blksize)
allocation = statp->st_blksize;
#endif
and
#define _G_BUFSIZ 8192
#define _IO_BUFSIZ _G_BUFSIZ
# define BUFSIZ _IO_BUFSIZ
so the default buffer is 4 * 8192 = 32768
(except in the unlikely case of blocks > 32k....)
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Diffstat (limited to 'fs/xfs')
-rw-r--r-- | fs/xfs/linux-2.6/xfs_file.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c index e4caeb2..3805ada 100644 --- a/fs/xfs/linux-2.6/xfs_file.c +++ b/fs/xfs/linux-2.6/xfs_file.c @@ -203,9 +203,9 @@ xfs_file_readdir( * * Try to give it an estimate that's good enough, maybe at some * point we can change the ->readdir prototype to include the - * buffer size. + * buffer size. For now we use the current glibc buffer size. */ - bufsize = (size_t)min_t(loff_t, PAGE_SIZE, ip->i_d.di_size); + bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size); error = xfs_readdir(ip, dirent, bufsize, (xfs_off_t *)&filp->f_pos, filldir); |