diff options
author | jeff <jeff@FreeBSD.org> | 2004-11-18 08:44:09 +0000 |
---|---|---|
committer | jeff <jeff@FreeBSD.org> | 2004-11-18 08:44:09 +0000 |
commit | 9caab2e84389f65b9ff83b89b6b9842c315c524b (patch) | |
tree | a2660fd5e71e5a909689ab2e6917d6e1d47d5b55 /sys/nfsclient/nfs_bio.c | |
parent | dbceb16b545647d0b326249600ce96d92cd056d5 (diff) | |
download | FreeBSD-src-9caab2e84389f65b9ff83b89b6b9842c315c524b.zip FreeBSD-src-9caab2e84389f65b9ff83b89b6b9842c315c524b.tar.gz |
- Eliminate the acquisition and release of the bqlock in bremfree() by
setting the B_REMFREE flag in the buf. This is done to prevent lock order
reversals with code that must call bremfree() with a local lock held.
This also reduces overhead by removing two lock operations per buf for
fsync() and similar.
- Check for the B_REMFREE flag in brelse() and bqrelse() after the bqlock
has been acquired so that we may remove ourself from the free-list.
- Provide a bremfreef() function to immediately remove a buf from a
free-list for use only by NFS. This is done because the nfsclient code
overloads the b_freelist queue for its own async. io queue.
- Simplify the numfreebuffers accounting by removing a switch statement
that executed the same code in every possible case.
- getnewbuf() can encounter locked bufs on free-lists once Giant is removed.
Remove a panic associated with this condition and delay asserts that
inspect the buf until after it is locked.
Reviewed by: phk
Sponsored by: Isilon Systems, Inc.
Diffstat (limited to 'sys/nfsclient/nfs_bio.c')
-rw-r--r-- | sys/nfsclient/nfs_bio.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sys/nfsclient/nfs_bio.c b/sys/nfsclient/nfs_bio.c index 1ae3157..56e2cb6 100644 --- a/sys/nfsclient/nfs_bio.c +++ b/sys/nfsclient/nfs_bio.c @@ -1241,6 +1241,8 @@ again: bp->b_wcred = crhold(cred); } + if (bp->b_flags & B_REMFREE) + bremfreef(bp); BUF_KERNPROC(bp); TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); nmp->nm_bufqlen++; |