Moving this to tech@
Hi,
I was studying the scheduler code after watching tedu's talk, I'd like
to expose this statistics to userland so that I can try playing with
cache affinity in the future:
gimli:src: sysctl kern.schedstat
kern.schedstat.nmigrations=23744
kern.schedstat.noidle=0
kern.schedstat.stolen=9170
kern.schedstat.choose=834843
kern.schedstat.wasidle=808711
kern.schedstat.nomigrations=2388
Opinions ?
Index: sys/sys//sched.h
===================================================================
RCS file: /cvs/src/sys/sys/sched.h,v
retrieving revision 1.29
diff -d -u -p -w -r1.29 sched.h
--- sys/sys//sched.h 7 Jul 2011 18:00:33 -0000 1.29
+++ sys/sys//sched.h 12 Nov 2011 13:51:04 -0000
@@ -75,6 +75,34 @@
* Posix defines a <sched.h> which may want to include <sys/sched.h>
*/
+struct schedstat {
+ u_int64_t scs_nmigrations;
+ u_int64_t scs_noidle;
+ u_int64_t scs_stolen;
+
+ u_int64_t scs_choose;
+ u_int64_t scs_wasidle;
+ u_int64_t scs_nomigrations;
+};
+
+/* These sysctl names are only really used by sysctl(8) */
+#define KERN_SCHEDSTAT_NMIGRATIONS 1
+#define KERN_SCHEDSTAT_NOIDLE 2
+#define KERN_SCHEDSTAT_STOLEN 3
+#define KERN_SCHEDSTAT_CHOOSE 4
+#define KERN_SCHEDSTAT_WASIDLE 5
+#define KERN_SCHEDSTAT_NOMIGRATIONS 6
+#define KERN_SCHEDSTAT_MAXID 7
+
+#define CTL_KERN_SCHEDSTAT_NAMES { \
+ { 0, 0 }, \
+ { "nmigrations", CTLTYPE_QUAD }, \
+ { "noidle", CTLTYPE_QUAD }, \
+ { "stolen", CTLTYPE_QUAD }, \
+ { "choose", CTLTYPE_QUAD }, \
+ { "wasidle", CTLTYPE_QUAD }, \
+ { "nomigrations", CTLTYPE_QUAD } \
+}
/*
* CPU states.
* XXX Not really scheduler state, but no other good place to put
Index: sys/sys//sysctl.h
===================================================================
RCS file: /cvs/src/sys/sys/sysctl.h,v
retrieving revision 1.117
diff -d -u -p -w -r1.117 sysctl.h
--- sys/sys//sysctl.h 30 Aug 2011 01:09:29 -0000 1.117
+++ sys/sys//sysctl.h 12 Nov 2011 13:40:45 -0000
@@ -189,7 +189,8 @@ struct ctlname {
#define KERN_CONSDEV 75 /* dev_t: console terminal
device */
#define KERN_NETLIVELOCKS 76 /* int: number of network
livelocks */
#define KERN_POOL_DEBUG 77 /* int: enable pool_debug */
-#define KERN_MAXID 78 /* number of valid kern ids */
+#define KERN_SCHEDSTAT 78 /* struct: sched statistics */
+#define KERN_MAXID 79 /* number of valid kern ids */
#define CTL_KERN_NAMES { \
{ 0, 0 }, \
@@ -270,6 +271,7 @@ struct ctlname {
{ "consdev", CTLTYPE_STRUCT }, \
{ "netlivelocks", CTLTYPE_INT }, \
{ "pool_debug", CTLTYPE_INT }, \
+ { "schedstat", CTLTYPE_STRUCT }, \
}
/*
Index: sys/kern//kern_sched.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_sched.c,v
retrieving revision 1.24
diff -d -u -p -w -r1.24 kern_sched.c
--- sys/kern//kern_sched.c 12 Oct 2011 18:30:09 -0000 1.24
+++ sys/kern//kern_sched.c 12 Nov 2011 14:41:59 -0000
@@ -35,6 +35,8 @@ void sched_kthreads_create(void *);
int sched_proc_to_cpu_cost(struct cpu_info *ci, struct proc *p);
struct proc *sched_steal_proc(struct cpu_info *);
+struct schedstat schedstat;
+
/*
* To help choosing which cpu should run which process we keep track
* of cpus which are currently idle and which cpus have processes
@@ -301,14 +303,6 @@ again:
return (p);
}
-uint64_t sched_nmigrations;
-uint64_t sched_noidle;
-uint64_t sched_stolen;
-
-uint64_t sched_choose;
-uint64_t sched_wasidle;
-uint64_t sched_nomigrations;
-
struct cpu_info *
sched_choosecpu_fork(struct proc *parent, int flags)
{
@@ -374,7 +368,7 @@ sched_choosecpu(struct proc *p)
if (p->p_flag & P_CPUPEG)
return (p->p_cpu);
- sched_choose++;
+ schedstat.scs_choose++;
/*
* Look at all cpus that are currently idle and have nothing queued.
@@ -393,7 +387,7 @@ sched_choosecpu(struct proc *p)
if (cpuset_isset(&set, p->p_cpu) ||
(p->p_cpu == curcpu() && p->p_cpu->ci_schedstate.spc_nrun == 0 &&
curproc == p)) {
- sched_wasidle++;
+ schedstat.scs_wasidle++;
return (p->p_cpu);
}
@@ -411,9 +405,9 @@ sched_choosecpu(struct proc *p)
}
if (p->p_cpu != choice)
- sched_nmigrations++;
+ schedstat.scs_nmigrations++;
else
- sched_nomigrations++;
+ schedstat.scs_nomigrations++;
return (choice);
}
@@ -461,7 +455,7 @@ sched_steal_proc(struct cpu_info *self)
remrunqueue(best);
best->p_cpu = self;
- sched_stolen++;
+ schedstat.scs_stolen++;
return (best);
}
Index: sys/kern//kern_sysctl.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.208
diff -d -u -p -w -r1.208 kern_sysctl.c
--- sys/kern//kern_sysctl.c 18 Sep 2011 13:23:38 -0000 1.208
+++ sys/kern//kern_sysctl.c 12 Nov 2011 15:04:52 -0000
@@ -112,6 +112,7 @@ extern struct disklist_head disklist;
extern fixpt_t ccpu;
extern long numvnodes;
extern u_int mcllivelocks;
+extern struct schedstat schedstat;
extern void nmbclust_update(void);
@@ -602,6 +603,9 @@ kern_sysctl(int *name, u_int namelen, vo
pool_reclaim_all();
return (error);
}
+ case KERN_SCHEDSTAT:
+ return (sysctl_rdstruct(oldp, oldlenp, newp, &schedstat,
+ sizeof(struct schedstat)));
default:
return (EOPNOTSUPP);
}
Index: sbin/sysctl//sysctl.c
===================================================================
RCS file: /cvs/src/sbin/sysctl/sysctl.c,v
retrieving revision 1.180
diff -d -u -p -w -r1.180 sysctl.c
--- sbin/sysctl//sysctl.c 16 Sep 2011 20:52:48 -0000 1.180
+++ sbin/sysctl//sysctl.c 12 Nov 2011 14:22:19 -0000
@@ -119,6 +119,7 @@ struct ctlname username[] = CTL_USER_NAM
struct ctlname debugname[CTL_DEBUG_MAXID];
struct ctlname kernmallocname[] = CTL_KERN_MALLOC_NAMES;
struct ctlname forkstatname[] = CTL_KERN_FORKSTAT_NAMES;
+struct ctlname schedstatname[] = CTL_KERN_SCHEDSTAT_NAMES;
struct ctlname nchstatsname[] = CTL_KERN_NCHSTATS_NAMES;
struct ctlname ttysname[] = CTL_KERN_TTY_NAMES;
struct ctlname semname[] = CTL_KERN_SEMINFO_NAMES;
@@ -198,6 +199,7 @@ static int sysctl_vfsgen(char *, char **
int sysctl_bios(char *, char **, int *, int, int *);
int sysctl_swpenc(char *, char **, int *, int, int *);
int sysctl_forkstat(char *, char **, int *, int, int *);
+int sysctl_schedstat(char *, char **, int *, int, int *);
int sysctl_tty(char *, char **, int *, int, int *);
int sysctl_nchstats(char *, char **, int *, int, int *);
int sysctl_malloc(char *, char **, int *, int, int *);
@@ -450,6 +452,9 @@ parse(char *string, int flags)
case KERN_NETLIVELOCKS:
special |= UNSIGNED;
break;
+ case KERN_SCHEDSTAT:
+ sysctl_schedstat(string, &bufp, mib, flags, &type);
+ return;
}
break;
@@ -1622,6 +1627,7 @@ struct list pipexlist = { pipexname, PIP
struct list kernmalloclist = { kernmallocname, KERN_MALLOC_MAXID };
struct list forkstatlist = { forkstatname, KERN_FORKSTAT_MAXID };
+struct list schedstatlist = { schedstatname, KERN_SCHEDSTAT_MAXID };
struct list nchstatslist = { nchstatsname, KERN_NCHSTATS_MAXID };
struct list ttylist = { ttysname, KERN_TTY_MAXID };
struct list semlist = { semname, KERN_SEMINFO_MAXID };
@@ -1891,6 +1897,62 @@ sysctl_malloc(char *string, char **bufpp
*typep = CTLTYPE_STRING;
return (3);
}
+ return (-1);
+}
+
+/*
+ * handle scheduler statistics
+ */
+int
+sysctl_schedstat(char *string, char **bufpp, int mib[], int flags, int *typep)
+{
+ static struct schedstat scs;
+ static int keepvalue = 0;
+ int indx;
+ size_t size;
+
+ if (*bufpp == NULL) {
+ bzero(&scs, sizeof(scs));
+ listall(string, &schedstatlist);
+ return (-1);
+ }
+ if ((indx = findname(string, "third", bufpp, &schedstatlist)) == -1)
+ return (-1);
+ if (*bufpp != NULL) {
+ warnx("fourth level name in %s is invalid", string);
+ return (-1);
+ }
+ if (keepvalue == 0) {
+ size = sizeof(scs);
+ if (sysctl(mib, 2, &scs, &size, NULL, 0) < 0)
+ return (-1);
+ keepvalue = 1;
+ }
+ if (!nflag)
+ (void)printf("%s%s", string, equ);
+ switch (indx) {
+ case KERN_SCHEDSTAT_NMIGRATIONS:
+ (void)printf("%llu\n", scs.scs_nmigrations);
+ break;
+ case KERN_SCHEDSTAT_NOIDLE:
+ (void)printf("%llu\n", scs.scs_noidle);
+ break;
+ case KERN_SCHEDSTAT_STOLEN:
+ (void)printf("%llu\n", scs.scs_stolen);
+ break;
+ case KERN_SCHEDSTAT_CHOOSE:
+ (void)printf("%llu\n", scs.scs_choose);
+ break;
+ case KERN_SCHEDSTAT_WASIDLE:
+ (void)printf("%llu\n", scs.scs_wasidle);
+ break;
+ case KERN_SCHEDSTAT_NOMIGRATIONS:
+ (void)printf("%llu\n", scs.scs_nomigrations);
+ break;
+ default:
+ break;
+ }
+
return (-1);
}
