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| author | ivoras <ivoras@FreeBSD.org> | 2010-08-09 22:56:10 +0000 |
|---|---|---|
| committer | ivoras <ivoras@FreeBSD.org> | 2010-08-09 22:56:10 +0000 |
| commit | 191f678b275b29567df10893ca0b343b09edd2c0 (patch) | |
| tree | e5efacfc7bb067c51efb542607d4bb1d830f7b7a /sys/kern/vfs_cluster.c | |
| parent | fa067e3c3039de4e253b44dc547cbf0f9f9fb3f8 (diff) | |
| download | FreeBSD-src-191f678b275b29567df10893ca0b343b09edd2c0.zip FreeBSD-src-191f678b275b29567df10893ca0b343b09edd2c0.tar.gz | |
Bumping the read-ahead count once more, to value equivalent to 512 KiB on
most system, based on benchmark results on a low-end fibre channel SAN
under VMWare:
vfs.read_max read performance
8 (historical default) 83 MB/s
16 (recent bump) 131 MB/s
32 (this version) 152 MB/s
64 157 MB/s
(results are +/- 3 MB/s)
As read-ahead is heuristic, based on past IO requests, it shouldn't be
problematic. The new default is still smaller then in other OSes.
Diffstat (limited to 'sys/kern/vfs_cluster.c')
| -rw-r--r-- | sys/kern/vfs_cluster.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sys/kern/vfs_cluster.c b/sys/kern/vfs_cluster.c index 469bc7e..ba331b1 100644 --- a/sys/kern/vfs_cluster.c +++ b/sys/kern/vfs_cluster.c @@ -71,7 +71,7 @@ static int write_behind = 1; SYSCTL_INT(_vfs, OID_AUTO, write_behind, CTLFLAG_RW, &write_behind, 0, "Cluster write-behind; 0: disable, 1: enable, 2: backed off"); -static int read_max = 16; +static int read_max = 32; SYSCTL_INT(_vfs, OID_AUTO, read_max, CTLFLAG_RW, &read_max, 0, "Cluster read-ahead max block count"); |
