make check_interval adaptive

yamt · Jun 18, 2023 · 3f9a06e · 3f9a06e
1 parent b112428
commit 3f9a06e
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Showing 4 changed files with 63 additions and 7 deletions.
diff --git a/lib/exec.c b/lib/exec.c
@@ -897,8 +897,6 @@ restart_insn(struct exec_context *ctx)
 #endif
 }
 
-#define CHECK_INTERVAL 1000
-
 int
 check_interrupt(struct exec_context *ctx)
 {
@@ -952,6 +950,34 @@ check_interrupt(struct exec_context *ctx)
         return 0;
 }
 
+#define CHECK_INTERVAL_MAX UINT32_MAX
+#define CHECK_INTERVAL_DEFAULT 1000
+#define CHECK_INTERVAL_MIN 1
+
+static void
+adjust_check_interval(struct exec_context *ctx, const struct timespec *now,
+                      const struct timespec *last)
+{
+        struct timespec diff;
+        timespec_sub(now, last, &diff);
+        uint64_t diff_ms = timespec_to_ms(&diff);
+        uint32_t check_interval = ctx->check_interval;
+        if (diff_ms < CHECK_INTERRUPT_INTERVAL_MS / 2) {
+                if (check_interval <= CHECK_INTERVAL_MAX / 2) {
+                        check_interval *= 2;
+                } else {
+                        check_interval = CHECK_INTERVAL_MAX;
+                }
+        } else if (diff_ms / 2 > CHECK_INTERRUPT_INTERVAL_MS) {
+                check_interval /= 2;
+                if (check_interval < CHECK_INTERVAL_MIN) {
+                        check_interval = CHECK_INTERVAL_MIN;
+                }
+        }
+        xlog_trace("check_interval %" PRIu32, check_interval);
+        ctx->check_interval = check_interval;
+}
+
 int
 exec_expr(uint32_t funcidx, const struct expr *expr,
           const struct localtype *localtype,
@@ -979,7 +1005,10 @@ exec_expr(uint32_t funcidx, const struct expr *expr,
 int
 exec_expr_continue(struct exec_context *ctx)
 {
-        uint32_t n = 0;
+        struct timespec last;
+        bool has_last = false;
+        uint32_t n = ctx->check_interval;
+        assert(n > 0);
         while (true) {
                 int ret;
                 switch (ctx->event) {
@@ -1043,16 +1072,27 @@ exec_expr_continue(struct exec_context *ctx)
                 if (ctx->frames.lsize == 0) {
                         break;
                 }
-                n++;
-                if (__predict_false(n > CHECK_INTERVAL)) {
-                        n = 0;
+                n--;
+                if (__predict_false(n == 0)) {
                         ret = check_interrupt(ctx);
                         if (ret != 0) {
                                 if (IS_RESTARTABLE(ret)) {
                                         STAT_INC(ctx->stats.exec_loop_restart);
                                 }
                                 return ret;
                         }
+                        struct timespec now;
+                        ret = timespec_now(CLOCK_MONOTONIC, &now);
+                        if (ret != 0) {
+                                return ret;
+                        }
+                        if (has_last) {
+                                adjust_check_interval(ctx, &now, &last);
+                        }
+                        last = now;
+                        has_last = true;
+                        n = ctx->check_interval;
+                        assert(n > 0);
                 }
                 struct cell *stack = &VEC_NEXTELEM(ctx->stack);
                 ret = fetch_exec_next_insn(ctx->p, stack, ctx);
@@ -1275,6 +1315,7 @@ exec_context_init(struct exec_context *ctx, struct instance *inst)
         report_init(&ctx->report0);
         ctx->report = &ctx->report0;
         ctx->restart_type = RESTART_NONE;
+        ctx->check_interval = CHECK_INTERVAL_DEFAULT;
         exec_options_set_defaults(&ctx->options);
 }
 

diff --git a/lib/exec_context.h b/lib/exec_context.h
@@ -198,6 +198,7 @@ struct exec_context {
         struct cluster *cluster;
         unsigned int user_intr_delay_count;
         unsigned int user_intr_delay;
+        uint32_t check_interval;
 
         /* scheduler */
         struct sched *sched;

diff --git a/lib/timeutil.c b/lib/timeutil.c
@@ -219,6 +219,20 @@ convert_timespec(clockid_t from_id, clockid_t to_id,
         return ret;
 }
 
+uint64_t
+timespec_to_ms(const struct timespec *tv)
+{
+        if (UINT64_MAX / 1000 < tv->tv_sec) {
+                return UINT64_MAX;
+        }
+        uint64_t ms1 = tv->tv_sec * 1000;
+        uint64_t ms2 = tv->tv_nsec / 1000000;
+        if (UINT64_MAX - ms1 < ms2) {
+                return UINT64_MAX;
+        }
+        return ms1 + ms2;
+}
+
 int
 timespec_sleep(clockid_t id, const struct timespec *absto)
 {

diff --git a/lib/timeutil.h b/lib/timeutil.h
@@ -20,5 +20,5 @@ int abstime_to_reltime_ms_roundup(clockid_t id, const struct timespec *abstime,
                                   int *reltime_ms);
 int convert_timespec(clockid_t from_id, clockid_t to_id,
                      const struct timespec *from_ts, struct timespec *result);
-
+uint64_t timespec_to_ms(const struct timespec *tv);
 int timespec_sleep(clockid_t id, const struct timespec *absto);