From 0d14b65c785757387aa6e75157e63bdd8bb2a0bc Mon Sep 17 00:00:00 2001 From: attilio Date: Fri, 21 Dec 2012 13:14:12 +0000 Subject: Fixup r218424: uio_yield() was scaling directly to userland priority. When kern_yield() was introduced with the possibility to specify a new priority, the behaviour changed by not lowering priority at all in the consumers, making the yielding mechanism highly ineffective for high priority kthreads like bufdaemon, syncer, vlrudaemon, etc. There are no evidences that consumers could bear with such change in semantic and this situation could finally lead to bugs similar to the ones fixed in r244240. Re-specify userland pri for kthreads involved. Tested by: pho Reviewed by: kib, mdf MFC after: 1 week --- sys/kern/vfs_bio.c | 2 +- sys/kern/vfs_mount.c | 2 +- sys/kern/vfs_subr.c | 8 ++++---- 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'sys/kern') diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 32a1089..96c8442 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -2209,7 +2209,7 @@ buf_daemon() while (numdirtybuffers > lodirtybuffers) { if (buf_do_flush(NULL) == 0) break; - kern_yield(PRI_UNCHANGED); + kern_yield(PRI_USER); } lodirtybuffers = lodirtysave; diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index abae339..97b92f8 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -1724,7 +1724,7 @@ __mnt_vnode_next(struct vnode **mvp, struct mount *mp) KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); if (should_yield()) { MNT_IUNLOCK(mp); - kern_yield(PRI_UNCHANGED); + kern_yield(PRI_USER); MNT_ILOCK(mp); } vp = TAILQ_NEXT(*mvp, v_nmntvnodes); diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index 64d75fb..683daed 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -741,7 +741,7 @@ next_iter: continue; MNT_IUNLOCK(mp); yield: - kern_yield(PRI_UNCHANGED); + kern_yield(PRI_USER); relock_mnt: MNT_ILOCK(mp); } @@ -853,7 +853,7 @@ vnlru_proc(void) vnlru_nowhere++; tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3); } else - kern_yield(PRI_UNCHANGED); + kern_yield(PRI_USER); } } @@ -4635,7 +4635,7 @@ __mnt_vnode_next_all(struct vnode **mvp, struct mount *mp) struct vnode *vp; if (should_yield()) - kern_yield(PRI_UNCHANGED); + kern_yield(PRI_USER); MNT_ILOCK(mp); KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); vp = TAILQ_NEXT(*mvp, v_nmntvnodes); @@ -4784,7 +4784,7 @@ __mnt_vnode_next_active(struct vnode **mvp, struct mount *mp) { if (should_yield()) - kern_yield(PRI_UNCHANGED); + kern_yield(PRI_USER); mtx_lock(&vnode_free_list_mtx); return (mnt_vnode_next_active(mvp, mp)); } -- cgit v1.1