From e03abc0c963a31cb07dfbc07c7d85d75e0d13cf4 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Sun, 11 Feb 2007 13:21:39 -0600 Subject: 9p: implement optional loose read cache While cacheing is generally frowned upon in the 9p world, it has its place -- particularly in situations where the remote file system is exclusive and/or read-only. The vacfs views of venti content addressable store are a real-world instance of such a situation. To facilitate higher performance for these workloads (and eventually use the fscache patches), we have enabled a "loose" cache mode which does not attempt to maintain any form of consistency on the page-cache or dcache. This results in over two orders of magnitude performance improvement for cacheable block reads in the Bonnie benchmark. The more aggressive use of the dcache also seems to improve metadata operational performance. Signed-off-by: Eric Van Hensbergen --- fs/9p/v9fs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'fs/9p/v9fs.c') diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index d9b561ba5e58..6ad6f192b6e4 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -53,6 +53,8 @@ enum { Opt_uname, Opt_remotename, /* Options that take no arguments */ Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd, + /* Cache options */ + Opt_cache_loose, /* Error token */ Opt_err }; @@ -76,6 +78,8 @@ static match_table_t tokens = { {Opt_fd, "fd"}, {Opt_legacy, "noextend"}, {Opt_nodevmap, "nodevmap"}, + {Opt_cache_loose, "cache=loose"}, + {Opt_cache_loose, "loose"}, {Opt_err, NULL} }; @@ -106,6 +110,7 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses) v9ses->debug = 0; v9ses->rfdno = ~0; v9ses->wfdno = ~0; + v9ses->cache = 0; if (!options) return; @@ -121,7 +126,6 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses) "integer field, but no integer?\n"); continue; } - } switch (token) { case Opt_port: @@ -169,6 +173,9 @@ static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses) case Opt_nodevmap: v9ses->nodev = 1; break; + case Opt_cache_loose: + v9ses->cache = CACHE_LOOSE; + break; default: continue; } -- cgit v1.2.3