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Use a name instead of a magic number for kern_yield(9) when the priority

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should not change.  Fetch the td_user_pri under the thread lock.  This
is probably not necessary but a magic number also seems preferable to
knowing the implementation details here.

Requested by:	Jason Behmer < jason DOT behmer AT isilon DOT com >
This commit is contained in:
Matthew D Fleming 2011-05-13 05:27:58 +00:00
parent c4f9a10590
commit 3d08a76bbc
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=221829
8 changed files with 16 additions and 8 deletions
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4
sys/kern/kern_synch.c
View File

@ -551,7 +551,7 @@ maybe_yield(void)
{
if (should_yield())
kern_yield(curthread->td_user_pri);
kern_yield(PRI_USER);
}
void
@ -562,6 +562,8 @@ kern_yield(int prio)
td = curthread;
DROP_GIANT();
thread_lock(td);
if (prio == PRI_USER)
prio = td->td_user_pri;
if (prio >= 0)
sched_prio(td, prio);
mi_switch(SW_VOL | SWT_RELINQUISH, NULL);

2
sys/kern/kern_sysctl.c
View File

@ -1590,7 +1590,7 @@ userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
SYSCTL_XUNLOCK();
if (error != EAGAIN)
break;
kern_yield(curthread->td_user_pri);
kern_yield(PRI_USER);
}
CURVNET_RESTORE();

2
sys/kern/vfs_bio.c
View File

@ -2234,7 +2234,7 @@ buf_daemon()
while (numdirtybuffers > lodirtybuffers) {
if (buf_do_flush(NULL) == 0)
break;
kern_yield(-1);
kern_yield(PRI_UNCHANGED);
}
lodirtybuffers = lodirtysave;

2
sys/kern/vfs_mount.c
View File

@ -1644,7 +1644,7 @@ __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(-1);
kern_yield(PRI_UNCHANGED);
MNT_ILOCK(mp);
}
vp = TAILQ_NEXT(*mvp, v_nmntvnodes);

4
sys/kern/vfs_subr.c
View File

@ -718,7 +718,7 @@ vlrureclaim(struct mount *mp)
continue;
MNT_IUNLOCK(mp);
yield:
kern_yield(-1);
kern_yield(PRI_UNCHANGED);
relock_mnt:
MNT_ILOCK(mp);
}
@ -831,7 +831,7 @@ vnlru_proc(void)
vnlru_nowhere++;
tsleep(vnlruproc, PPAUSE, "vlrup", hz * 3);
} else
kern_yield(-1);
kern_yield(PRI_UNCHANGED);
}
}

2
sys/kern/vfs_vnops.c
View File

@ -491,7 +491,7 @@ vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred,
break;
offset += chunk;
base = (char *)base + chunk;
kern_yield(curthread->td_user_pri);
kern_yield(PRI_USER);
} while (len);
if (aresid)
*aresid = len + iaresid;

6
sys/sys/priority.h
View File

@ -117,6 +117,12 @@
#define PRI_MIN_IDLE (224)
#define PRI_MAX_IDLE (PRI_MAX)
#ifdef _KERNEL
/* Other arguments for kern_yield(9). */
#define PRI_USER -2 /* Change to current user priority. */
#define PRI_UNCHANGED -1 /* Do not change priority. */
#endif
struct priority {
u_char pri_class; /* Scheduling class. */
u_char pri_level; /* Normal priority level. */

2
sys/ufs/ffs/ffs_softdep.c
View File

@ -1412,7 +1412,7 @@ softdep_process_worklist(mp, full)
*/
if (should_yield()) {
FREE_LOCK(&lk);
kern_yield(-1);
kern_yield(PRI_UNCHANGED);
bwillwrite();
ACQUIRE_LOCK(&lk);
}