lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

9p: implement optional loose read cache

Browse Source 
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 <ericvh@gmail.com>
This commit is contained in:
Eric Van Hensbergen
2007-02-11 13:21:39 -06:00
parent 2c0463a9ae
commit e03abc0c96
10 changed files with 88 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
fs/9p/vfs_file.c
View File

@ -79,6 +79,13 @@ int v9fs_file_open(struct inode *inode, struct file *file)
vfid->filp = file;
kfree(fcall);
if((vfid->qid.version) && (v9ses->cache)) {
dprintk(DEBUG_VFS, "cached");
/* enable cached file options */
if(file->f_op == &v9fs_file_operations)
file->f_op = &v9fs_cached_file_operations;
}
return 0;
Clunk_Fid:
@ -238,6 +245,17 @@ v9fs_file_write(struct file *filp, const char __user * data,
return total;
}
const struct file_operations v9fs_cached_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
.aio_read = generic_file_aio_read,
.write = v9fs_file_write,
.open = v9fs_file_open,
.release = v9fs_dir_release,
.lock = v9fs_file_lock,
.mmap = generic_file_mmap,
};
const struct file_operations v9fs_file_operations = {
.llseek = generic_file_llseek,
.read = v9fs_file_read,