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

NFS: Use cond_resched_lock() to reduce latencies in the commit scans

Browse Source 
Ensure that we conditionally drop the inode->i_lock when it is safe
to do so in the commit loops.
We do so after locking the nfs_page, but before removing it from the
commit list. We can then use list_safe_reset_next to recover the loop
after the lock is retaken.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust
2012-03-17 11:59:30 -04:00
parent 5ae67c4fee
commit 3b3be88d67
3 changed files with 20 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
fs/nfs/write.c
View File

@@ -561,7 +561,8 @@ nfs_need_commit(struct nfs_inode *nfsi)
/* i_lock held by caller */
static int
nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max)
nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max,
spinlock_t *lock)
{
struct nfs_page *req, *tmp;
int ret = 0;
@@ -569,6 +570,8 @@ nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max)
list_for_each_entry_safe(req, tmp, src, wb_list) {
if (!nfs_lock_request(req))
continue;
if (cond_resched_lock(lock))
list_safe_reset_next(req, tmp, wb_list);
nfs_request_remove_commit_list(req);
nfs_list_add_request(req, dst);
ret++;
@@ -596,8 +599,10 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst)
if (nfsi->ncommit > 0) {
const int max = INT_MAX;
ret = nfs_scan_commit_list(&nfsi->commit_list, dst, max);
ret += pnfs_scan_commit_lists(inode, max - ret);
ret = nfs_scan_commit_list(&nfsi->commit_list, dst, max,
&inode->i_lock);
ret += pnfs_scan_commit_lists(inode, max - ret,
&inode->i_lock);
}
spin_unlock(&inode->i_lock);
return ret;