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fix infinite loop when rtshare=0; fix a crash in Queue/CPU + best2; Added stat counter for sched and priority

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This commit is contained in:
Charlie Root 2019-09-15 04:57:34 -04:00
parent 638e096379
commit 7f31542099
3 changed files with 92 additions and 54 deletions
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47
sys/kern/kern_event.c
View File

@ -451,6 +451,7 @@ kevq_avail(struct kevq *kevq)
static inline struct kevq *
kevq_lock_check_avail(struct kevq *next_kevq)
{
CTR1(KTR_KQ, "kevq_lock_check_avail: kevq %p", next_kevq);
if (next_kevq != NULL) {
KEVQ_NOTOWNED(next_kevq);
KEVQ_LOCK(next_kevq);
@ -2420,7 +2421,9 @@ kevq_dump(struct sbuf *buf, struct kevq *kevq, int level)
"avg_events=\"%ld\" "
"total_fallbacks=\"%ld\" "
"total_mismatches=\"%ld\" "
"total_worksteal=\"%ld\" />\n",
"total_worksteal=\"%ld\" "
"total_realtime=\"%ld\" "
"total_sched=\"%ld\" />\n",
level * DUMP_INDENT, ' ', kevq, kevq->kn_count, kevq->kn_rt_count,
kevq->kevq_tot_time,
kevq->kevq_tot_syscall,
@ -2429,7 +2432,9 @@ kevq_dump(struct sbuf *buf, struct kevq *kevq, int level)
kevq->kevq_avg_ev,
kevq->kevq_tot_fallback,
kevq->kevq_tot_kqd_mismatch,
kevq->kevq_tot_ws);
kevq->kevq_tot_ws,
kevq->kevq_tot_realtime,
kevq->kevq_tot_sched);
}
static void
@ -2739,7 +2744,7 @@ kevq_worksteal(struct kevq *kevq)
tgt_count = KQSCHED_GET_FARGS(kq);
/* XXX: hack */
KASSERT(tgt_count < 8, ("too many kevq ws knotes"));
KASSERT(tgt_count <= 8, ("too many kevq ws knotes"));
KVLST_RLOCK(kq);
other_kevq = kevq_vec_select_kevq(&kq->kevq_vlist, 1);
@ -2765,7 +2770,6 @@ kevq_worksteal(struct kevq *kevq)
/* steal from the first because it arrived late */
ws_kn = kevq_peek_knote(other_kevq);
/* TODO: maybe limit the number of knotes to go through */
while((ws_count < tgt_count) && (ws_kn != NULL)) {
/* fast fail */
@ -2918,8 +2922,16 @@ kqueue_scan(struct kevq *kevq, int maxevents, struct kevent_copyops *k_ops,
/* adjust rtlimit according to the target share
* = ceil(maxevents * kq->kq_rtshare%)
*/
/* XXX: actually rtlimit can be 0 but we don't allow it yet/forever?
* the current implementation has an issue when only runtime events are present and rtlimit = 0
* since kevq_total_knotes returns > 0, but rtlimit = 0 so we don't dequeue any runtime event
* the function will be trapped infinitely in (wakeup because tot_ev > 0 -> dequeue normal marker -> count = 0 -> retry -> wakeup because tot ev > 0)
* We simply don't allow users to set rlimit to 0 so we at least hand back one rt event, otherwise the solution might be very complicated
* because it involves sleep waiting on different queues as rtshare changes, AND in RUNTIME too? Not worth it really.
*/
rtlimit = (maxevents * kq->kq_rtshare + 99) / 100;
KASSERT(rtlimit >= 0, ("the math above is fundamentally broken"));
KASSERT(rtlimit > 0, ("the math above is fundamentally broken"));
rsbt = 0;
if (tsp != NULL) {
@ -2976,7 +2988,7 @@ kqueue_scan(struct kevq *kevq, int maxevents, struct kevent_copyops *k_ops,
KEVQ_OWNED(kevq);
kevp = keva;
CTR3(KTR_KQ, "kqueue_scan: td %d on kevq %p has %d events", td->td_tid, kevq, kevq_total_knote(kevq));
CTR4(KTR_KQ, "kqueue_scan: td %d on kevq %p has %d events, max_ev %d", td->td_tid, kevq, kevq_total_knote(kevq), maxevents);
if (kevq_total_knote(kevq) == 0) {
if (fsbt == -1) {
@ -3048,7 +3060,9 @@ kqueue_scan(struct kevq *kevq, int maxevents, struct kevent_copyops *k_ops,
}
KEVQ_OWNED(kevq);
// if (kevq_total_knote(kevq) > 0) {
// KASSERT(!(TAILQ_FIRST(&kevq->kn_rt_head) == NULL && TAILQ_FIRST(&kevq->kn_head) == NULL), ("NULL > 0?"));
// }
/* quick check */
if (curr < rtlimit) {
rdrained = 0;
@ -3105,7 +3119,7 @@ kqueue_scan(struct kevq *kevq, int maxevents, struct kevent_copyops *k_ops,
/* Now we have exclusive access to kn */
TAILQ_REMOVE(kntq, kn, kn_tqe);
CTR3(KTR_KQ, "kqueue_scan: td %d on kevq %p dequeued knote %p", td->td_tid, kevq, kn);
CTR4(KTR_KQ, "kqueue_scan: td %d on kevq %p dequeued knote %p, curr %d", td->td_tid, kevq, kn, curr);
if ((kn->kn_status & KN_DISABLED) == KN_DISABLED) {
kn->kn_status &= ~(KN_QUEUED | KN_PROCESSING | KN_WS);
*kncnt -= 1;
@ -3117,7 +3131,7 @@ kqueue_scan(struct kevq *kevq, int maxevents, struct kevent_copyops *k_ops,
/* We are dequeuing our marker, wakeup threads waiting on it */
knote_flux_wakeup(kn);
KN_FLUX_UNLOCK(kn);
CTR2(KTR_KQ, "kqueue_scan: td %d MARKER WAKEUP %p", td->td_tid, kn);
CTR3(KTR_KQ, "kqueue_scan: td %d MARKER WAKEUP %p PRI %d", td->td_tid, kn, pri);
if (kn == rtmarker) {
rdrained = 1;
@ -3247,6 +3261,7 @@ kqueue_scan(struct kevq *kevq, int maxevents, struct kevent_copyops *k_ops,
if (pri) {
curr++;
kevq->kevq_tot_realtime++;
}
if (nkev == KQ_NEVENTS) {
@ -3395,7 +3410,7 @@ kqueue_ioctl(struct file *fp, u_long cmd, void *data,
switch KQTUNE_PARSE_OBJ(tune) {
case KQTUNE_RTSHARE:
tune = KQTUNE_PARSE_ARGS(tune);
if (tune >= 0 && tune <= 100)
if (tune > 0 && tune <= 100)
kq->kq_rtshare = tune;
else
error = (EINVAL);
@ -4530,14 +4545,18 @@ knote_next_kevq(struct knote *kn)
if (sargs > 0) {
KVLST_RLOCK(kq);
other_kevq = kevq_vec_select_kevq(&kq->kevq_vlist, sargs);
KVLST_RUNLOCK(kq);
if (next_kevq == NULL || (other_kevq != NULL && kevq_lat_wcmp(next_kevq, other_kevq, 90) > 0)) {
next_kevq = other_kevq;
}
}
next_kevq = kevq_lock_check_avail(next_kevq);
next_kevq = kevq_lock_check_avail(next_kevq);
/* need to unlock after kevq lock acquire because other_kevq might be drained too */
if (sargs > 0) {
KVLST_RUNLOCK(kq);
}
KQD_RUNLOCK(kqd);
if (kqd_mismatch && next_kevq != NULL) {
@ -4583,8 +4602,10 @@ knote_next_kevq(struct knote *kn)
CTR2(KTR_KQ, "knote_next_kevq: [RAND] next kevq %p for kn %p", next_kevq, kn);
}
if (next_kevq != NULL)
if (next_kevq != NULL) {
KEVQ_OWNED(next_kevq);
next_kevq->kevq_tot_sched++;
}
return next_kevq;
}

47
sys/sys/eventvar.h
View File

@ -49,6 +49,31 @@
#define KQDIR_INACTIVE (1)
struct kevq {
/* 1st cacheline */
/* Sched stats */
uint64_t kevq_avg_lat;
uint64_t kevq_avg_ev;
uint64_t kevq_tot_ev;
uint64_t kevq_tot_time;
uint64_t kevq_tot_syscall;
uint64_t kevq_last_kev;
uint32_t kevq_last_nkev;
#define KEVQ_SLEEP 0x01
#define KEVQ_CLOSING 0x02
#define KEVQ_ACTIVE 0x04
#define KEVQ_WS 0x08 /* the kevq is work stealing */
int kevq_state;
int kn_count; /* number of pending knotes */
int kn_rt_count; /* number of runtime knotes */
/* 2nd cacheline */
uint64_t kevq_tot_ws;
/* TODO: maybe these should be in kqdomain or global */
uint64_t kevq_tot_fallback;
uint64_t kevq_tot_kqd_mismatch;
uint64_t kevq_tot_sched;
uint64_t kevq_tot_realtime;
LIST_ENTRY(kevq) kevq_th_e; /* entry into kevq_thred's hashtable */
LIST_ENTRY(kevq) kq_e; /* entry into kq */
LIST_ENTRY(kevq) kevq_th_tqe; /* entry into kevq_thred's kevq_list */
@ -61,29 +86,7 @@ struct kevq {
struct knote kn_marker;
struct ktailq kn_rt_head; /* list of pending knotes with runtime priority */
struct knote kn_marker_rt;
int kn_count; /* number of pending knotes */
int kn_rt_count; /* number of runtime knotes */
#define KEVQ_SLEEP 0x01
#define KEVQ_CLOSING 0x02
#define KEVQ_ACTIVE 0x04
#define KEVQ_WS 0x08 /* the kevq is work stealing */
int kevq_state;
int kevq_refcnt;
uint64_t kevq_last_kev;
uint64_t kevq_last_nkev;
/* Sched stats */
uint64_t kevq_avg_lat;
uint64_t kevq_avg_ev;
uint64_t kevq_tot_ev;
uint64_t kevq_tot_time;
uint64_t kevq_tot_syscall;
uint64_t kevq_tot_ws;
/* TODO: maybe these should be in kqdomain or global */
uint64_t kevq_tot_fallback;
uint64_t kevq_tot_kqd_mismatch;
};
/* TODO: assumed that threads don't get rescheduled across cores */

52
tests/sys/kqueue/libkqueue/read_m.c
View File

@ -325,12 +325,14 @@ test_socket_queue(void)
tid++;
group[i][j].evcnt = 0;
group[i][j].group_id = i;
pthread_create(&group[i][j].thrd, NULL, test_socket_queue_thrd, &group[i][j]);
pthread_attr_t attr;
pthread_attr_init(&attr);
CPU_ZERO(&cpuset);
CPU_SET(i, &cpuset);
if (pthread_setaffinity_np(group[i][j].thrd, sizeof(cpuset_t), &cpuset) < 0) {
if (pthread_attr_setaffinity_np(&attr, sizeof(cpuset_t), &cpuset) < 0) {
err(1, "thread_affinity");
}
pthread_create(&group[i][j].thrd, &attr, test_socket_queue_thrd, &group[i][j]);
#ifdef TEST_DEBUG
printf("READ_M: created and affinitized thread %d to core group %d\n", group[i][j].tid, i);
#endif
@ -636,10 +638,10 @@ test_socket_ws_timeout()
/***************************
* Brutal test
***************************/
#define THREAD_BRUTE_CNT (16)
#define SOCK_BRUTE_CNT (128)
#define PACKET_BRUTE_CNT (50 * (SOCK_BRUTE_CNT))
#define THREAD_EXIT_PROB (67)
#define THREAD_BRUTE_CNT (8)
#define SOCK_BRUTE_CNT (512)
#define PACKET_BRUTE_CNT (100 * (SOCK_BRUTE_CNT))
#define THREAD_EXIT_PROB (50)
#define BRUTE_REALTIME_PROB (50)
#define BRUTE_MAX_FREQ (10000)
#define BRUTE_MIN_FREQ (1)
@ -776,7 +778,7 @@ test_socket_brutal(char* name)
int error;
int val;
val = KQTUNE_MAKE(KQTUNE_RTSHARE, rand() % 100);
val = KQTUNE_MAKE(KQTUNE_RTSHARE, (rand() % 100) + 1);
error = ioctl(g_kqfd, FKQTUNE, &val);
if (error == -1) {
err(1, "ioctl TUNE");
@ -894,7 +896,7 @@ test_socket_realtime()
socket_push(socks[i][1], '.');
}
for (int i = 0; i <= 100; i++) {
for (int i = 1; i <= 100; i++) {
test_socket_rt_share(kqfd, 4, i);
}
@ -933,10 +935,32 @@ test_evfilt_read_m()
if (error == -1) {
err(1, "ioctl");
}
test_socket_queue();
//test_socket_queue();
test_socket_brutal("queue0");
close(g_kqfd);
/* Queue + bo2*/
flags = KQSCHED_MAKE(KQ_SCHED_QUEUE,2, 0, 0);
g_kqfd = kqueue();
error = ioctl(g_kqfd, FKQMULTI, &flags);
if (error == -1) {
err(1, "ioctl");
}
//test_socket_queue();
test_socket_brutal("queue2");
close(g_kqfd);
/* Queue + bo2 + ws */
flags = KQSCHED_MAKE(KQ_SCHED_QUEUE,2, KQ_SCHED_FEAT_WS, 1);
g_kqfd = kqueue();
error = ioctl(g_kqfd, FKQMULTI, &flags);
if (error == -1) {
err(1, "ioctl");
}
//test_socket_queue();
test_socket_brutal("queue2_ws");
close(g_kqfd);
/* CPU + Bo0 */
flags = KQSCHED_MAKE(KQ_SCHED_CPU,0,0,0);;
g_kqfd = kqueue();
@ -947,16 +971,6 @@ test_evfilt_read_m()
test_socket_brutal("cpu0");
close(g_kqfd);
/* CPU + Bo1 */
flags = KQSCHED_MAKE(KQ_SCHED_CPU,1,0,0);;
g_kqfd = kqueue();
error = ioctl(g_kqfd, FKQMULTI, &flags);
if (error == -1) {
err(1, "ioctl");
}
test_socket_brutal("cpu1");
close(g_kqfd);
/* CPU + Bo2 */
flags = KQSCHED_MAKE(KQ_SCHED_CPU,2,0,0);
g_kqfd = kqueue();