MINOR: debug: add "debug dev sched" to stress the scheduler.
This command supports starting a bunch of tasks or tasklets, either on the
current thread (mask=0), all (default), or any set, either single-threaded
or multi-threaded, and possibly auto-scheduled.
These tasks/tasklets will randomly pick another one to wake it up. The
tasks only do it 50% of the time while tasklets always wake two tasks up,
in order to achieve roughly 50% load (since the target might already be
woken up).
diff --git a/src/debug.c b/src/debug.c
index 7f2d167..aaba9ca 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -675,6 +675,210 @@
return 1;
}
+static struct task *debug_task_handler(struct task *t, void *ctx, unsigned short state)
+{
+ unsigned long *tctx = ctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }
+ unsigned long inter = tctx[1];
+ unsigned long rnd;
+
+ t->expire = tick_add(now_ms, inter);
+
+ /* half of the calls will wake up another entry */
+ rnd = ha_random64();
+ if (rnd & 1) {
+ rnd >>= 1;
+ rnd %= tctx[0];
+ rnd = tctx[rnd + 2];
+
+ if (rnd & 1)
+ task_wakeup((struct task *)(rnd - 1), TASK_WOKEN_MSG);
+ else
+ tasklet_wakeup((struct tasklet *)rnd);
+ }
+ return t;
+}
+
+static struct task *debug_tasklet_handler(struct task *t, void *ctx, unsigned short state)
+{
+ unsigned long *tctx = ctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }
+ unsigned long rnd;
+ int i;
+
+ /* wake up two random entries */
+ for (i = 0; i < 2; i++) {
+ rnd = ha_random64() % tctx[0];
+ rnd = tctx[rnd + 2];
+
+ if (rnd & 1)
+ task_wakeup((struct task *)(rnd - 1), TASK_WOKEN_MSG);
+ else
+ tasklet_wakeup((struct tasklet *)rnd);
+ }
+ return t;
+}
+
+/* parse a "debug dev sched" command
+ * debug dev sched {task|tasklet} [count=<count>] [mask=<mask>] [single=<single>] [inter=<inter>]
+ */
+static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appctx, void *private)
+{
+ int arg;
+ void *ptr;
+ int size;
+ const char *word, *end;
+ struct ist name;
+ char *msg = NULL;
+ char *endarg;
+ unsigned long long new;
+ unsigned long count = 0;
+ unsigned long thrid = 0;
+ unsigned int inter = 0;
+ unsigned long mask, tmask;
+ unsigned long i;
+ int mode = 0; // 0 = tasklet; 1 = task
+ int single = 0;
+ unsigned long *tctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }
+
+ if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
+ return 1;
+
+ ptr = NULL; size = 0;
+ mask = all_threads_mask;
+
+ if (strcmp(args[3], "task") != 0 && strcmp(args[3], "tasklet") != 0) {
+ return cli_err(appctx,
+ "Usage: debug dev sched {task|tasklet} { <obj> = <value> }*\n"
+ " <obj> = {count | mask | inter | single }\n"
+ " <value> = 64-bit dec/hex integer (0x prefix supported)\n"
+ );
+ }
+
+ mode = strcmp(args[3], "task") == 0;
+
+ _HA_ATOMIC_ADD(&debug_commands_issued, 1);
+ for (arg = 4; *args[arg]; arg++) {
+ end = word = args[arg];
+ while (*end && *end != '=' && *end != '^' && *end != '+' && *end != '-')
+ end++;
+ name = ist2(word, end - word);
+ if (isteq(name, ist("count"))) {
+ ptr = &count; size = sizeof(count);
+ } else if (isteq(name, ist("mask"))) {
+ ptr = &mask; size = sizeof(mask);
+ } else if (isteq(name, ist("tid"))) {
+ ptr = &thrid; size = sizeof(thrid);
+ } else if (isteq(name, ist("inter"))) {
+ ptr = &inter; size = sizeof(inter);
+ } else if (isteq(name, ist("single"))) {
+ ptr = &single; size = sizeof(single);
+ } else
+ return cli_dynerr(appctx, memprintf(&msg, "Unsupported setting: '%s'.\n", word));
+
+ /* parse the new value . */
+ new = strtoll(end + 1, &endarg, 0);
+ if (end[1] && *endarg) {
+ memprintf(&msg,
+ "%sIgnoring unparsable value '%s' for field '%.*s'.\n",
+ msg ? msg : "", end + 1, (int)(end - word), word);
+ continue;
+ }
+
+ /* write the new value */
+ if (size == 8)
+ write_u64(ptr, new);
+ else if (size == 4)
+ write_u32(ptr, new);
+ else if (size == 2)
+ write_u16(ptr, new);
+ else
+ *(uint8_t *)ptr = new;
+ }
+
+ tctx = calloc(sizeof(*tctx), count + 2);
+ if (!tctx)
+ goto fail;
+
+ tctx[0] = (unsigned long)count;
+ tctx[1] = (unsigned long)inter;
+
+ mask &= all_threads_mask;
+ if (!mask)
+ mask = tid_bit;
+
+ tmask = 0;
+ for (i = 0; i < count; i++) {
+ if (single || mode == 0) {
+ /* look for next bit matching a bit in mask or loop back to zero */
+ for (tmask <<= 1; !(mask & tmask); ) {
+ if (!(mask & -tmask))
+ tmask = 1;
+ else
+ tmask <<= 1;
+ }
+ } else {
+ /* multi-threaded task */
+ tmask = mask;
+ }
+
+ /* now, if poly or mask was set, tmask corresponds to the
+ * valid thread mask to use, otherwise it remains zero.
+ */
+ //printf("%lu: mode=%d mask=%#lx\n", i, mode, tmask);
+ if (mode == 0) {
+ struct tasklet *tl = tasklet_new();
+
+ if (!tl)
+ goto fail;
+
+ if (tmask)
+ tl->tid = my_ffsl(tmask) - 1;
+ tl->process = debug_tasklet_handler;
+ tl->context = tctx;
+ tctx[i + 2] = (unsigned long)tl;
+ } else {
+ struct task *task = task_new(tmask ? tmask : tid_bit);
+
+ if (!task)
+ goto fail;
+
+ task->process = debug_task_handler;
+ task->context = tctx;
+ tctx[i + 2] = (unsigned long)task + 1;
+ }
+ }
+
+ /* start the tasks and tasklets */
+ for (i = 0; i < count; i++) {
+ unsigned long ctx = tctx[i + 2];
+
+ if (ctx & 1)
+ task_wakeup((struct task *)(ctx - 1), TASK_WOKEN_INIT);
+ else
+ tasklet_wakeup((struct tasklet *)ctx);
+ }
+
+ if (msg && *msg)
+ return cli_dynmsg(appctx, LOG_INFO, msg);
+ return 1;
+
+ fail:
+ /* free partially allocated entries */
+ for (i = 0; tctx && i < count; i++) {
+ unsigned long ctx = tctx[i + 2];
+
+ if (!ctx)
+ break;
+
+ if (ctx & 1)
+ task_destroy((struct task *)(ctx - 1));
+ else
+ tasklet_free((struct tasklet *)ctx);
+ }
+
+ free(tctx);
+ return cli_err(appctx, "Not enough memory");
+}
+
#if defined(DEBUG_MEM_STATS)
/* CLI parser for the "debug dev memstats" command */
static int debug_parse_cli_memstats(char **args, char *payload, struct appctx *appctx, void *private)
@@ -917,6 +1121,7 @@
{{ "debug", "dev", "memstats", NULL }, "debug dev memstats [reset|all] : dump/reset memory statistics", debug_parse_cli_memstats, debug_iohandler_memstats, NULL, NULL, ACCESS_EXPERT },
#endif
{{ "debug", "dev", "panic", NULL }, "debug dev panic : immediately trigger a panic", debug_parse_cli_panic, NULL, NULL, NULL, ACCESS_EXPERT },
+ {{ "debug", "dev", "sched", NULL }, "debug dev sched ... : stress the scheduler", debug_parse_cli_sched, NULL, NULL, NULL, ACCESS_EXPERT },
{{ "debug", "dev", "stream",NULL }, "debug dev stream ... : show/manipulate stream flags", debug_parse_cli_stream,NULL, NULL, NULL, ACCESS_EXPERT },
{{ "debug", "dev", "tkill", NULL }, "debug dev tkill [thr] [sig] : send signal to thread", debug_parse_cli_tkill, NULL, NULL, NULL, ACCESS_EXPERT },
{{ "debug", "dev", "write", NULL }, "debug dev write [size] : write that many bytes", debug_parse_cli_write, NULL, NULL, NULL, ACCESS_EXPERT },