PERFORCE change 61923 for review
Julian Elischer
julian at FreeBSD.org
Tue Sep 21 18:55:37 PDT 2004
http://perforce.freebsd.org/chv.cgi?CH=61923
Change 61923 by julian at julian_ref on 2004/09/22 01:54:47
Use slot counting macros for ULE too.
Allow preempted threads to get back quicker by puting them
at the HEAD of their run queue list instead of the end.
Affected files ...
.. //depot/projects/nsched/sys/kern/kern_switch.c#37 edit
.. //depot/projects/nsched/sys/kern/kern_synch.c#16 edit
.. //depot/projects/nsched/sys/kern/sched_4bsd.c#58 edit
.. //depot/projects/nsched/sys/kern/sched_ule.c#36 edit
.. //depot/projects/nsched/sys/sys/proc.h#34 edit
.. //depot/projects/nsched/sys/sys/runq.h#2 edit
Differences ...
==== //depot/projects/nsched/sys/kern/kern_switch.c#37 (text+ko) ====
@@ -581,9 +581,7 @@
}
/*
- * Our thread state says that we are already on a run queue, so
- * update our state as if we had been dequeued by choosethread().
- * However we must not actually be on the system run queue yet.
+ * Thread is runnable but not yet put on system run queue.
*/
MPASS(TD_ON_RUNQ(td));
MPASS(td->td_sched->ke_state != KES_ONRUNQ);
@@ -606,7 +604,7 @@
TD_SET_RUNNING(td);
CTR3(KTR_PROC, "preempting to thread %p (pid %d, %s)\n", td,
td->td_proc->p_pid, td->td_proc->p_comm);
- mi_switch(SW_INVOL, td);
+ mi_switch(SW_INVOL|SW_PREEMPT, td);
return (1);
#else
return (0);
@@ -706,7 +704,7 @@
* corresponding status bit.
*/
void
-runq_add(struct runq *rq, struct kse *ke)
+runq_add(struct runq *rq, struct kse *ke, int flags)
{
struct rqhead *rqh;
int pri;
@@ -717,7 +715,11 @@
rqh = &rq->rq_queues[pri];
CTR5(KTR_RUNQ, "runq_add: td=%p ke=%p pri=%d %d rqh=%p",
ke->ke_thread, ke, ke->ke_thread->td_priority, pri, rqh);
- TAILQ_INSERT_TAIL(rqh, ke, ke_procq);
+ if (flags & SRQ_PREEMPTED) {
+ TAILQ_INSERT_HEAD(rqh, ke, ke_procq);
+ } else {
+ TAILQ_INSERT_TAIL(rqh, ke, ke_procq);
+ }
}
/*
==== //depot/projects/nsched/sys/kern/kern_synch.c#16 (text+ko) ====
==== //depot/projects/nsched/sys/kern/sched_4bsd.c#58 (text+ko) ====
@@ -128,8 +128,8 @@
kg, \
kg->kg_concurrency, \
kg->kg_avail_opennings); \
- KASSERT((kg->kg_avail_opennings <= kg->kg_concurrency), \
- ("slots out of whack")); \
+/* KASSERT((kg->kg_avail_opennings <= kg->kg_concurrency), \
+ ("slots out of whack"));*/ \
} while (0)
#define SLOT_USE(kg) \
@@ -141,8 +141,8 @@
kg, \
kg->kg_concurrency, \
kg->kg_avail_opennings); \
- KASSERT((kg->kg_avail_opennings >= 0), \
- ("slots out of whack")); \
+/* KASSERT((kg->kg_avail_opennings >= 0), \
+ ("slots out of whack"));*/ \
} while (0)
/*
@@ -831,7 +831,9 @@
SLOT_RELEASE(td->td_ksegrp);
if (TD_IS_RUNNING(td)) {
/* Put us back on the run queue (kse and all). */
- setrunqueue(td, SRQ_OURSELF|SRQ_YIELDING);
+ setrunqueue(td, (flags & SW_PREEMPT) ?
+ SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
+ SRQ_OURSELF|SRQ_YIELDING);
} else if (p->p_flag & P_HADTHREADS) {
/*
* We will not be on the run queue. So we must be
@@ -1057,7 +1059,7 @@
if ((td->td_proc->p_flag & P_NOLOAD) == 0)
sched_tdcnt++;
SLOT_USE(td->td_ksegrp);
- runq_add(ke->ke_runq, ke);
+ runq_add(ke->ke_runq, ke, flags);
ke->ke_ksegrp->kg_runq_kses++;
ke->ke_state = KES_ONRUNQ;
maybe_resched(td);
==== //depot/projects/nsched/sys/kern/sched_ule.c#36 (text+ko) ====
@@ -164,6 +164,32 @@
#define kg_runtime kg_sched->skg_runtime
#define kg_slptime kg_sched->skg_slptime
+#define SLOT_RELEASE(kg) \
+do { \
+ kg->kg_avail_opennings++; \
+ CTR5(KTR_RUNQ, "%s line %d: kg %p(%d) Slot released (->%d)", \
+ __FUNCTION__, \
+ __LINE__, \
+ kg, \
+ kg->kg_concurrency, \
+ kg->kg_avail_opennings); \
+ KASSERT((kg->kg_avail_opennings <= kg->kg_concurrency), \
+ ("slots out of whack")); \
+} while (0)
+
+#define SLOT_USE(kg) \
+do { \
+ kg->kg_avail_opennings--; \
+ CTR5(KTR_RUNQ, "%s line %d: kg %p(%d) Slot used (->%d)", \
+ __FUNCTION__, \
+ __LINE__, \
+ kg, \
+ kg->kg_concurrency, \
+ kg->kg_avail_opennings); \
+ KASSERT((kg->kg_avail_opennings >= 0), \
+ ("slots out of whack")); \
+} while (0)
+
static struct kse kse0;
static struct kg_sched kg_sched0;
@@ -383,7 +409,7 @@
ke->ke_flags |= KEF_XFERABLE;
}
#endif
- runq_add(ke->ke_runq, ke);
+ runq_add(ke->ke_runq, ke, 0);
}
static __inline void
@@ -874,7 +900,7 @@
runq_remove(ke->ke_runq, ke);
sched_slice(ke);
ke->ke_runq = kseq->ksq_next;
- runq_add(ke->ke_runq, ke);
+ runq_add(ke->ke_runq, ke, 0);
continue;
}
return (ke);
@@ -1149,9 +1175,9 @@
/*
* Set up the scheduler specific parts of proc0.
*/
+ proc0.p_sched = NULL; /* XXX */
ksegrp0.kg_sched = &kg_sched0;
- proc0.p_sched = NULL; /* XXX */
- thread0.td_kse = &kse0;
+ thread0.td_sched = &kse0;
kse0.ke_thread = &thread0;
kse0.ke_oncpu = NOCPU; /* wrong.. can we use PCPU(cpuid) yet? */
kse0.ke_state = KES_THREAD;
@@ -1210,7 +1236,7 @@
ke->ke_runq != KSEQ_CPU(ke->ke_cpu)->ksq_curr) {
runq_remove(ke->ke_runq, ke);
ke->ke_runq = KSEQ_CPU(ke->ke_cpu)->ksq_curr;
- runq_add(ke->ke_runq, ke);
+ runq_add(ke->ke_runq, ke, 0);
}
/*
* Hold this kse on this cpu so that sched_prio() doesn't
@@ -1238,15 +1264,6 @@
td->td_pflags &= ~TDP_OWEPREEMPT;
/*
- * If we bring in a thread,
- * then account for it as if it had been added to the run queue and then chosen.
- */
- if (newtd) {
- newtd->td_ksegrp->kg_avail_opennings--;
- newtd->td_kse->ke_flags |= KEF_DIDRUN;
- TD_SET_RUNNING(newtd);
- }
- /*
* If the KSE has been assigned it may be in the process of switching
* to the new cpu. This is the case in sched_bind().
*/
@@ -1255,7 +1272,7 @@
TD_SET_CAN_RUN(td);
} else {
/* We are ending our run so make our slot available again */
- td->td_ksegrp->kg_avail_opennings++;
+ SLOT_RELEASE(td->td_ksegrp);
if (TD_IS_RUNNING(td)) {
kseq_load_rem(KSEQ_CPU(ke->ke_cpu), ke);
/*
@@ -1272,16 +1289,29 @@
/*
* We will not be on the run queue.
* So we must be sleeping or similar.
+ * Don't use the slot if we will need it
+ * for newtd.
*/
- if (td->td_proc->p_flag & P_HADTHREADS)
+ if ((td->td_proc->p_flag & P_HADTHREADS) &&
+ (newtd == NULL ||
+ newtd->td_ksegrp != td->td_ksegrp))
slot_fill(td->td_ksegrp);
}
}
}
- if (newtd != NULL)
+ if (newtd != NULL) {
+ /*
+ * If we bring in a thread,
+ * then account for it as if it had been added to the
+ * run queue and then chosen.
+ */
+ SLOT_USE(newtd->td_ksegrp);
+ newtd->td_kse->ke_flags |= KEF_DIDRUN;
+ TD_SET_RUNNING(newtd);
kseq_load_add(KSEQ_SELF(), newtd->td_kse);
- else
+ } else {
newtd = choosethread();
+ }
if (td != newtd)
cpu_switch(td, newtd);
sched_lock.mtx_lock = (uintptr_t)td;
@@ -1773,7 +1803,7 @@
curthread->td_flags |= TDF_NEEDRESCHED;
if (preemptive && maybe_preempt(td))
return;
- td->td_ksegrp->kg_avail_opennings--;
+ SLOT_USE(td->td_ksegrp);
ke->ke_ksegrp->kg_runq_threads++;
ke->ke_state = KES_ONRUNQ;
==== //depot/projects/nsched/sys/sys/proc.h#34 (text+ko) ====
@@ -652,12 +652,14 @@
/* Flags for mi_switch(). */
#define SW_VOL 0x0001 /* Voluntary switch. */
#define SW_INVOL 0x0002 /* Involuntary switch. */
+#define SW_PREEMPT 0x0004 /* The invol switch is a preemption */
/* flags for setrunqueue(). Why are we setting this thread on the run queue? */
#define SRQ_BORING 0x0000 /* No special circumstances */
#define SRQ_YIELDING 0x0001 /* we are yielding (from mi_switch) */
#define SRQ_OURSELF 0x0002 /* it is ourself (from mi_switch) */
#define SRQ_INTR 0x0004 /* it is probably urgent */
+#define SRQ_PREEMPTED 0x0008 /* has been preempted.. be kind */
/* How values for thread_single(). */
#define SINGLE_NO_EXIT 0
==== //depot/projects/nsched/sys/sys/runq.h#2 (text+ko) ====
@@ -62,7 +62,7 @@
struct rqhead rq_queues[RQ_NQS];
};
-void runq_add(struct runq *, struct kse *);
+void runq_add(struct runq *, struct kse *, int flags);
int runq_check(struct runq *);
struct kse *runq_choose(struct runq *);
void runq_init(struct runq *);
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