MINOR: pool: make the thread-local hot cache size configurable
Till now it was only possible to change the thread local hot cache size
at build time using CONFIG_HAP_POOL_CACHE_SIZE. But along benchmarks it
was sometimes noticed a huge contention in the lower level memory
allocators indicating that larger caches could be beneficial, especially
on machines with large L2 CPUs.
Given that the checks against this value was no longer on a hot path
anymore, there was no reason for continuing to force it to be tuned at
build time. So this patch allows to set it by tune.memory-hot-size.
It's worth noting that during the boot phase the value remains zero so
that it's possible to know if the value was set or not, which opens the
possibility that we try to automatically adjust it based on the per-cpu
L2 cache size or the use of certain protocols (none of this is done yet).
diff --git a/src/pool.c b/src/pool.c
index e225d21..df9d060 100644
--- a/src/pool.c
+++ b/src/pool.c
@@ -517,7 +517,7 @@
while ((ph->count && full) ||
(ph->count >= CONFIG_HAP_POOL_CLUSTER_SIZE &&
ph->count >= 16 + pool_cache_count / 8 &&
- pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE * 3 / 4)) {
+ pool_cache_bytes > global.tune.pool_cache_size * 3 / 4)) {
pool_evict_last_items(pool, ph, CONFIG_HAP_POOL_CLUSTER_SIZE);
}
}
@@ -546,7 +546,7 @@
BUG_ON(pool != ph->pool);
pool_evict_last_items(pool, ph, CONFIG_HAP_POOL_CLUSTER_SIZE);
- } while (pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE * 7 / 8);
+ } while (pool_cache_bytes > global.tune.pool_cache_size * 7 / 8);
}
/* Frees an object to the local cache, possibly pushing oldest objects to the
@@ -572,10 +572,10 @@
pool_cache_count++;
pool_cache_bytes += pool->size;
- if (unlikely(pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE * 3 / 4)) {
+ if (unlikely(pool_cache_bytes > global.tune.pool_cache_size * 3 / 4)) {
if (ph->count >= 16 + pool_cache_count / 8 + CONFIG_HAP_POOL_CLUSTER_SIZE)
pool_evict_from_local_cache(pool, 0);
- if (pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE)
+ if (pool_cache_bytes > global.tune.pool_cache_size)
pool_evict_from_local_caches();
}
}
@@ -790,7 +790,8 @@
}
#endif
- if (unlikely(pool_debugging & POOL_DBG_NO_CACHE)) {
+ if (unlikely((pool_debugging & POOL_DBG_NO_CACHE) ||
+ global.tune.pool_cache_size < pool->size)) {
pool_free_nocache(pool, ptr);
return;
}
@@ -1211,6 +1212,26 @@
return 0;
}
+/* config parser for global "tune.memory.hot-size" */
+static int mem_parse_global_hot_size(char **args, int section_type, struct proxy *curpx,
+ const struct proxy *defpx, const char *file, int line,
+ char **err)
+{
+ long size;
+
+ if (too_many_args(1, args, err, NULL))
+ return -1;
+
+ size = atol(args[1]);
+ if (size <= 0) {
+ memprintf(err, "'%s' expects a strictly positive value.", args[0]);
+ return -1;
+ }
+
+ global.tune.pool_cache_size = size;
+ return 0;
+}
+
/* config parser for global "no-memory-trimming" */
static int mem_parse_global_no_mem_trim(char **args, int section_type, struct proxy *curpx,
const struct proxy *defpx, const char *file, int line,
@@ -1225,6 +1246,7 @@
/* register global config keywords */
static struct cfg_kw_list mem_cfg_kws = {ILH, {
{ CFG_GLOBAL, "tune.fail-alloc", mem_parse_global_fail_alloc },
+ { CFG_GLOBAL, "tune.memory.hot-size", mem_parse_global_hot_size },
{ CFG_GLOBAL, "no-memory-trimming", mem_parse_global_no_mem_trim },
{ 0, NULL, NULL }
}};