HPA: add size-exclusion functionality.

I.e. only allowing allocations under or over certain sizes.

include/jemalloc/internal/hpa.h

@@ -59,6 +59,17 @@ struct hpa_shard_s {
 	 * fragmentation avoidance measure.
 	 */
 	size_t ps_alloc_max;
+	/*
+	 * What's the maximum size we'll try to allocate out of the shard at
+	 * all?
+	 */
+	size_t small_max;
+	/*
+	 * What's the minimum size for which we'll go straight to the global
+	 * arena?
+	 */
+	size_t large_min;
+
 	/* The arena ind we're associated with. */
 	unsigned ind;
 };
@@ -67,7 +78,7 @@ bool hpa_init(hpa_t *hpa, base_t *base, emap_t *emap,
     edata_cache_t *edata_cache);
 bool hpa_shard_init(hpa_shard_t *shard, hpa_t *hpa,
     edata_cache_t *edata_cache, unsigned ind, size_t ps_goal,
-    size_t ps_alloc_max);
+    size_t ps_alloc_max, size_t small_max, size_t large_min);
 void hpa_shard_destroy(tsdn_t *tsdn, hpa_shard_t *shard);
 
 /*

include/jemalloc/internal/jemalloc_internal_externs.h

@@ -15,6 +15,8 @@ extern bool opt_confirm_conf;
 extern bool opt_hpa;
 extern size_t opt_hpa_slab_goal;
 extern size_t opt_hpa_slab_max_alloc;
+extern size_t opt_hpa_small_max;
+extern size_t opt_hpa_large_min;
 extern const char *opt_junk;
 extern bool opt_junk_alloc;
 extern bool opt_junk_free;

include/jemalloc/internal/pa.h

@@ -124,7 +124,7 @@ bool pa_shard_init(tsdn_t *tsdn, pa_shard_t *shard, emap_t *emap, base_t *base,
  * that we can boot without worrying about the HPA, then turn it on in a0.
  */
 bool pa_shard_enable_hpa(pa_shard_t *shard, hpa_t *hpa, size_t ps_goal,
-    size_t ps_alloc_max);
+    size_t ps_alloc_max, size_t small_max, size_t large_min);
 /*
  * We stop using the HPA when custom extent hooks are installed, but still
  * redirect deallocations to it.