Date: Sun, 26 Jan 2003 15:39:58 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Jeff Roberson <jroberson@chesapeake.net>, Julian Elischer <julian@elischer.org>, Steve Kargl <sgk@troutmask.apl.washington.edu>, Robert Watson <rwatson@FreeBSD.ORG>, Gary Jennejohn <garyj@jennejohn.org>, <arch@FreeBSD.ORG> Subject: Re: New scheduler - ULE performance w/ cpu stealing & no pickcpu Message-ID: <200301262339.h0QNdwK1069471@apollo.backplane.com> References: <20030126040154.A64928-100000@mail.chesapeake.net> <200301262045.h0QKjsVc067308@apollo.backplane.com>
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Here are the complete test results, the latest is with the stealcpu
code plus pickcpu ripped out. The results without pickcpu are
basically the same as with pickcpu (as expected).
-Matt
/usr/bin/time make -j 8 buildworld (local /usr/src, local usr/obj)
4BSD - Original scheduler
2414.84 real 2648.92 user 758.28 sys
2399.05 real 2647.84 user 757.78 sys
ULE -
3435.42 real 2500.73 user 581.20 sys
3343.95 real 2501.86 user 581.67 sys
ULE - STEALCPU/CHOOSE
2489.76 real 2610.33 user 659.74 sys
ULE - STEALCPU/CHOOSE, WITHOUT PICKCPU
2486.76 real 2613.67 user 668.31 sys
2470.49 real 2611.28 user 665.16 sys
Index: sched_ule.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/sched_ule.c,v
retrieving revision 1.1
diff -u -r1.1 sched_ule.c
--- sched_ule.c 26 Jan 2003 05:23:15 -0000 1.1
+++ sched_ule.c 26 Jan 2003 20:46:22 -0000
@@ -53,6 +53,9 @@
/* XXX This is bogus compatability crap for ps */
static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
+static int sched_stealcpu = 1;
+SYSCTL_INT(_kern, OID_AUTO, sched_stealcpu, CTLFLAG_RW, &sched_stealcpu, 0,
+ "Ok to steal KSEs from another cpu (0=disabled, 1=normal)");
static void sched_setup(void *dummy);
SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL)
@@ -181,7 +184,6 @@
static int sched_slice(struct ksegrp *kg);
static int sched_priority(struct ksegrp *kg);
void sched_pctcpu_update(struct kse *ke);
-int sched_pickcpu(void);
static void
sched_setup(void *dummy)
@@ -279,40 +281,6 @@
ke->ke_ftick = ke->ke_ltick - SCHED_CPU_TICKS;
}
-#ifdef SMP
-int
-sched_pickcpu(void)
-{
- int cpu;
- int load;
- int i;
-
- if (!smp_started)
- return (0);
-
- cpu = PCPU_GET(cpuid);
- load = kseq_cpu[cpu].ksq_load;
-
- for (i = 0; i < mp_maxid; i++) {
- if (CPU_ABSENT(i))
- continue;
- if (kseq_cpu[i].ksq_load < load) {
- cpu = i;
- load = kseq_cpu[i].ksq_load;
- }
- }
-
- CTR1(KTR_RUNQ, "sched_pickcpu: %d", cpu);
- return (cpu);
-}
-#else
-int
-sched_pickcpu(void)
-{
- return (0);
-}
-#endif
-
void
sched_prio(struct thread *td, u_char prio)
{
@@ -444,7 +412,6 @@
child->kg_user_pri = kg->kg_user_pri;
ckse->ke_slice = pkse->ke_slice;
- ckse->ke_oncpu = sched_pickcpu();
ckse->ke_runq = NULL;
/*
* Claim that we've been running for one second for statistical
@@ -554,9 +521,26 @@
cpu = PCPU_GET(cpuid);
kseq = &kseq_cpu[cpu];
- if (runq_check(kseq->ksq_curr) == 0)
- return (runq_check(kseq->ksq_next));
- return (1);
+ if (runq_check(kseq->ksq_curr))
+ return(1);
+ if (runq_check(kseq->ksq_next))
+ return(1);
+
+#ifdef SMP
+ /*
+ * Check other cpus for runnable tasks
+ */
+ if (sched_stealcpu) {
+ for (cpu = 0; cpu < mp_ncpus; ++cpu) {
+ kseq = &kseq_cpu[cpu];
+ if (runq_check(kseq->ksq_curr))
+ return(1);
+ if (runq_check(kseq->ksq_next))
+ return(1);
+ }
+ }
+#endif
+ return (0);
}
void
@@ -573,30 +557,53 @@
}
}
+static __inline
struct kse *
-sched_choose(void)
+sched_choose_kseq(struct kseq *kseq)
{
- struct kseq *kseq;
struct kse *ke;
struct runq *swap;
- int cpu;
- cpu = PCPU_GET(cpuid);
- kseq = &kseq_cpu[cpu];
-
if ((ke = runq_choose(kseq->ksq_curr)) == NULL) {
swap = kseq->ksq_curr;
kseq->ksq_curr = kseq->ksq_next;
kseq->ksq_next = swap;
ke = runq_choose(kseq->ksq_curr);
}
+ return(ke);
+}
+
+struct kse *
+sched_choose(void)
+{
+ struct kseq *kseq;
+ struct kse *ke;
+ int cpu, i;
+
+ cpu = PCPU_GET(cpuid);
+ kseq = &kseq_cpu[cpu];
+
+ ke = sched_choose_kseq(kseq);
if (ke) {
runq_remove(ke->ke_runq, ke);
ke->ke_state = KES_THREAD;
}
-
- return (ke);
+#ifdef SMP
+ else if (sched_stealcpu) {
+ for (i = mp_ncpus - 1; ke == NULL && i; --i) {
+ cpu = (cpu + 1) % mp_ncpus;
+ kseq = &kseq_cpu[cpu];
+ ke = sched_choose_kseq(kseq);
+ }
+ if (ke) {
+ runq_remove(ke->ke_runq, ke);
+ ke->ke_state = KES_THREAD;
+ }
+ }
+#endif
+ return(ke);
}
+
void
sched_add(struct kse *ke)
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