From b05c401ff68275ba4139861a825c545cc7464da4 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Tue, 23 Jun 2015 06:12:14 +0000 Subject: [PATCH] Only take previous buffer queue lock (olock) when needed for REMFREE in binsfree(). Submitted by: Conrad Meyer Sponsored by: EMC / Isilon Storage Division Review: https://reviews.freebsd.org/D2882 MFC after: 1 week --- sys/kern/vfs_bio.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 5ac04acfb0d..c715725f926 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -994,21 +994,23 @@ binsfree(struct buf *bp, int qindex) BUF_ASSERT_XLOCKED(bp); - olock = bqlock(bp->b_qindex); nlock = bqlock(qindex); - mtx_lock(olock); /* Handle delayed bremfree() processing. */ - if (bp->b_flags & B_REMFREE) + if (bp->b_flags & B_REMFREE) { + olock = bqlock(bp->b_qindex); + mtx_lock(olock); bremfreel(bp); + if (olock != nlock) { + mtx_unlock(olock); + mtx_lock(nlock); + } + } else + mtx_lock(nlock); if (bp->b_qindex != QUEUE_NONE) panic("binsfree: free buffer onto another queue???"); bp->b_qindex = qindex; - if (olock != nlock) { - mtx_unlock(olock); - mtx_lock(nlock); - } if (bp->b_flags & B_AGE) TAILQ_INSERT_HEAD(&bufqueues[bp->b_qindex], bp, b_freelist); else