Merge pull request #11888 from ctiller/shardier
Autosize timer list shards
diff --git a/src/core/lib/iomgr/timer_generic.cc b/src/core/lib/iomgr/timer_generic.cc
index 2333f18..38ac66e 100644
--- a/src/core/lib/iomgr/timer_generic.cc
+++ b/src/core/lib/iomgr/timer_generic.cc
@@ -25,6 +25,7 @@
#include "src/core/lib/iomgr/timer.h"
#include <grpc/support/alloc.h>
+#include <grpc/support/cpu.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/sync.h>
@@ -37,8 +38,6 @@
#define INVALID_HEAP_INDEX 0xffffffffu
-#define LOG2_NUM_SHARDS 5
-#define NUM_SHARDS (1 << LOG2_NUM_SHARDS)
#define ADD_DEADLINE_SCALE 0.33
#define MIN_QUEUE_WINDOW_DURATION 0.01
#define MAX_QUEUE_WINDOW_DURATION 1
@@ -74,14 +73,16 @@
grpc_timer list;
} timer_shard;
+static size_t g_num_shards;
+
/* Array of timer shards. Whenever a timer (grpc_timer *) is added, its address
* is hashed to select the timer shard to add the timer to */
-static timer_shard g_shards[NUM_SHARDS];
+static timer_shard* g_shards;
/* Maintains a sorted list of timer shards (sorted by their min_deadline, i.e
* the deadline of the next timer in each shard).
* Access to this is protected by g_shared_mutables.mu */
-static timer_shard* g_shard_queue[NUM_SHARDS];
+static timer_shard** g_shard_queue;
#ifndef NDEBUG
@@ -241,6 +242,11 @@
void grpc_timer_list_init(grpc_exec_ctx* exec_ctx) {
uint32_t i;
+ g_num_shards = GPR_MIN(1, 2 * gpr_cpu_num_cores());
+ g_shards = (timer_shard*)gpr_zalloc(g_num_shards * sizeof(*g_shards));
+ g_shard_queue =
+ (timer_shard**)gpr_zalloc(g_num_shards * sizeof(*g_shard_queue));
+
g_shared_mutables.initialized = true;
g_shared_mutables.checker_mu = GPR_SPINLOCK_INITIALIZER;
gpr_mu_init(&g_shared_mutables.mu);
@@ -250,7 +256,7 @@
grpc_register_tracer(&grpc_timer_trace);
grpc_register_tracer(&grpc_timer_check_trace);
- for (i = 0; i < NUM_SHARDS; i++) {
+ for (i = 0; i < g_num_shards; i++) {
timer_shard* shard = &g_shards[i];
gpr_mu_init(&shard->mu);
grpc_time_averaged_stats_init(&shard->stats, 1.0 / ADD_DEADLINE_SCALE, 0.1,
@@ -267,17 +273,19 @@
}
void grpc_timer_list_shutdown(grpc_exec_ctx* exec_ctx) {
- int i;
+ size_t i;
run_some_expired_timers(
exec_ctx, GPR_ATM_MAX, NULL,
GRPC_ERROR_CREATE_FROM_STATIC_STRING("Timer list shutdown"));
- for (i = 0; i < NUM_SHARDS; i++) {
+ for (i = 0; i < g_num_shards; i++) {
timer_shard* shard = &g_shards[i];
gpr_mu_destroy(&shard->mu);
grpc_timer_heap_destroy(&shard->heap);
}
gpr_mu_destroy(&g_shared_mutables.mu);
gpr_tls_destroy(&g_last_seen_min_timer);
+ gpr_free(g_shards);
+ gpr_free(g_shard_queue);
g_shared_mutables.initialized = false;
}
@@ -311,7 +319,7 @@
g_shard_queue[shard->shard_queue_index - 1]->min_deadline) {
swap_adjacent_shards_in_queue(shard->shard_queue_index - 1);
}
- while (shard->shard_queue_index < NUM_SHARDS - 1 &&
+ while (shard->shard_queue_index < g_num_shards - 1 &&
shard->min_deadline >
g_shard_queue[shard->shard_queue_index + 1]->min_deadline) {
swap_adjacent_shards_in_queue(shard->shard_queue_index);
@@ -323,7 +331,7 @@
void grpc_timer_init(grpc_exec_ctx* exec_ctx, grpc_timer* timer,
grpc_millis deadline, grpc_closure* closure) {
int is_first_timer = 0;
- timer_shard* shard = &g_shards[GPR_HASH_POINTER(timer, NUM_SHARDS)];
+ timer_shard* shard = &g_shards[GPR_HASH_POINTER(timer, g_num_shards)];
timer->closure = closure;
timer->deadline = deadline;
@@ -417,7 +425,7 @@
return;
}
- timer_shard* shard = &g_shards[GPR_HASH_POINTER(timer, NUM_SHARDS)];
+ timer_shard* shard = &g_shards[GPR_HASH_POINTER(timer, g_num_shards)];
gpr_mu_lock(&shard->mu);
if (GRPC_TRACER_ON(grpc_timer_trace)) {
gpr_log(GPR_DEBUG, "TIMER %p: CANCEL pending=%s", timer,