Add batch allocation API

Makefile.in

@@ -191,6 +191,7 @@ TESTS_UNIT := \
 	$(srcroot)test/unit/background_thread.c \
 	$(srcroot)test/unit/background_thread_enable.c \
 	$(srcroot)test/unit/base.c \
+	$(srcroot)test/unit/batch_alloc.c \
 	$(srcroot)test/unit/binshard.c \
 	$(srcroot)test/unit/bitmap.c \
 	$(srcroot)test/unit/bit_util.c \
@@ -264,7 +265,8 @@ TESTS_UNIT := \
 	$(srcroot)test/unit/zero_reallocs.c
 ifeq (@enable_prof@, 1)
 TESTS_UNIT += \
-	$(srcroot)test/unit/arena_reset_prof.c
+	$(srcroot)test/unit/arena_reset_prof.c \
+	$(srcroot)test/unit/batch_alloc_prof.c
 endif
 TESTS_INTEGRATION := $(srcroot)test/integration/aligned_alloc.c \
 	$(srcroot)test/integration/allocated.c \

include/jemalloc/internal/jemalloc_internal_externs.h

@@ -54,6 +54,7 @@ void arena_migrate(tsd_t *tsd, unsigned oldind, unsigned newind);
 void iarena_cleanup(tsd_t *tsd);
 void arena_cleanup(tsd_t *tsd);
 void arenas_tdata_cleanup(tsd_t *tsd);
+size_t batch_alloc(void **ptrs, size_t num, size_t size, int flags);
 void jemalloc_prefork(void);
 void jemalloc_postfork_parent(void);
 void jemalloc_postfork_child(void);

include/jemalloc/internal/prof_inlines.h

@@ -229,6 +229,17 @@ prof_sample_aligned(const void *ptr) {
 	return ((uintptr_t)ptr & PAGE_MASK) == 0;
 }
 
+JEMALLOC_ALWAYS_INLINE bool
+prof_sampled(tsd_t *tsd, const void *ptr) {
+	prof_info_t prof_info;
+	prof_info_get(tsd, ptr, NULL, &prof_info);
+	bool sampled = (uintptr_t)prof_info.alloc_tctx > (uintptr_t)1U;
+	if (sampled) {
+		assert(prof_sample_aligned(ptr));
+	}
+	return sampled;
+}
+
 JEMALLOC_ALWAYS_INLINE void
 prof_free(tsd_t *tsd, const void *ptr, size_t usize,
     emap_alloc_ctx_t *alloc_ctx) {

include/jemalloc/internal/thread_event.h

@@ -274,7 +274,6 @@ te_prof_sample_event_lookahead_surplus(tsd_t *tsd, size_t usize,
 
 JEMALLOC_ALWAYS_INLINE bool
 te_prof_sample_event_lookahead(tsd_t *tsd, size_t usize) {
-	assert(usize == sz_s2u(usize));
 	return te_prof_sample_event_lookahead_surplus(tsd, usize, NULL);
 }
 

src/jemalloc.c

@@ -3916,6 +3916,123 @@ je_malloc_usable_size(JEMALLOC_USABLE_SIZE_CONST void *ptr) {
 	return ret;
 }
 
+static void
+batch_alloc_prof_sample_assert(tsd_t *tsd, size_t batch, size_t usize) {
+	assert(config_prof && opt_prof);
+	bool prof_sample_event = te_prof_sample_event_lookahead(tsd,
+	    batch * usize);
+	assert(!prof_sample_event);
+	size_t surplus;
+	prof_sample_event = te_prof_sample_event_lookahead_surplus(tsd,
+	    (batch + 1) * usize, &surplus);
+	assert(prof_sample_event);
+	assert(surplus < usize);
+}
+
+size_t
+batch_alloc(void **ptrs, size_t num, size_t size, int flags) {
+	LOG("core.batch_alloc.entry",
+	    "ptrs: %p, num: %zu, size: %zu, flags: %d", ptrs, num, size, flags);
+
+	tsd_t *tsd = tsd_fetch();
+	check_entry_exit_locking(tsd_tsdn(tsd));
+
+	size_t filled = 0;
+
+	if (unlikely(tsd == NULL || tsd_reentrancy_level_get(tsd) > 0)) {
+		goto label_done;
+	}
+
+	size_t alignment = MALLOCX_ALIGN_GET(flags);
+	size_t usize;
+	if (aligned_usize_get(size, alignment, &usize, NULL, false)) {
+		goto label_done;
+	}
+
+	szind_t ind = sz_size2index(usize);
+	if (unlikely(ind >= SC_NBINS)) {
+		/* No optimization for large sizes. */
+		void *p;
+		while (filled < num && (p = je_mallocx(size, flags)) != NULL) {
+			ptrs[filled++] = p;
+		}
+		goto label_done;
+	}
+
+	bool zero = zero_get(MALLOCX_ZERO_GET(flags), /* slow */ true);
+
+	unsigned arena_ind = mallocx_arena_get(flags);
+	arena_t *arena;
+	if (arena_get_from_ind(tsd, arena_ind, &arena)) {
+		goto label_done;
+	}
+	if (arena == NULL) {
+		arena = arena_choose(tsd, NULL);
+	} else {
+		/* When a manual arena is specified, bypass the tcache. */
+		flags |= MALLOCX_TCACHE_NONE;
+	}
+	if (unlikely(arena == NULL)) {
+		goto label_done;
+	}
+
+	while (filled < num) {
+		size_t batch = num - filled;
+		size_t surplus = SIZE_MAX; /* Dead store. */
+		bool prof_sample_event = config_prof && opt_prof
+		    && te_prof_sample_event_lookahead_surplus(tsd,
+		    batch * usize, &surplus);
+
+		if (prof_sample_event) {
+			/*
+			 * Adjust so that the batch does not trigger prof
+			 * sampling.
+			 */
+			batch -= surplus / usize + 1;
+			batch_alloc_prof_sample_assert(tsd, batch, usize);
+		}
+
+		size_t n = arena_fill_small_fresh(tsd_tsdn(tsd), arena,
+		    ind, ptrs + filled, batch, zero);
+		filled += n;
+
+		/*
+		 * For thread events other than prof sampling, trigger them as
+		 * if there's a single allocation of size (n * usize).  This is
+		 * fine because:
+		 * (a) these events do not alter the allocation itself, and
+		 * (b) it's possible that some event would have been triggered
+		 *     multiple times, instead of only once, if the allocations
+		 *     were handled individually, but it would do no harm (or
+		 *     even be beneficial) to coalesce the triggerings.
+		 */
+		thread_alloc_event(tsd, n * usize);
+
+		if (n < batch) { /* OOM */
+			break;
+		}
+
+		if (prof_sample_event) {
+			/*
+			 * The next allocation will be prof sampled.  The
+			 * thread event logic is handled within the mallocx()
+			 * call.
+			 */
+			void *p = je_mallocx(size, flags);
+			if (p == NULL) { /* OOM */
+				break;
+			}
+			assert(prof_sampled(tsd, p));
+			ptrs[filled++] = p;
+		}
+	}
+
+label_done:
+	check_entry_exit_locking(tsd_tsdn(tsd));
+	LOG("core.batch_alloc.exit", "result: %zu", filled);
+	return filled;
+}
+
 /*
  * End non-standard functions.
  */

test/unit/batch_alloc.c

@@ -0,0 +1,190 @@
+#include "test/jemalloc_test.h"
+
+#define BATCH_MAX ((1U << 16) + 1024)
+static void *ptrs[BATCH_MAX];
+
+#define PAGE_ALIGNED(ptr) (((uintptr_t)ptr & PAGE_MASK) == 0)
+
+static void
+verify_stats(bin_stats_t *before, bin_stats_t *after, size_t batch,
+    unsigned nregs) {
+	if (!config_stats) {
+		return;
+	}
+	if (config_prof && opt_prof) {
+		/*
+		 * Checking the stats when prof is on is feasible but
+		 * complicated, while checking the non-prof case suffices for
+		 * unit-test purpose.
+		 */
+		return;
+	}
+	expect_u64_eq(before->nmalloc + batch, after->nmalloc, "");
+	expect_u64_eq(before->nrequests + batch, after->nrequests, "");
+	expect_zu_eq(before->curregs + batch, after->curregs, "");
+	size_t nslab = batch / nregs;
+	size_t n_nonfull = 0;
+	if (batch % nregs != 0) {
+		++nslab;
+		++n_nonfull;
+	}
+	expect_u64_eq(before->nslabs + nslab, after->nslabs, "");
+	expect_zu_eq(before->curslabs + nslab, after->curslabs, "");
+	expect_zu_eq(before->nonfull_slabs + n_nonfull, after->nonfull_slabs,
+	    "");
+}
+
+static void
+verify_batch(tsd_t *tsd, void **ptrs, size_t batch, size_t usize, bool zero,
+    arena_t *arena, unsigned nregs) {
+	for (size_t i = 0, j = 0; i < batch; ++i, ++j) {
+		if (j == nregs) {
+			j = 0;
+		}
+		void *p = ptrs[i];
+		expect_zu_eq(isalloc(tsd_tsdn(tsd), p), usize, "");
+		expect_ptr_eq(iaalloc(tsd_tsdn(tsd), p), arena, "");
+		if (zero) {
+			for (size_t k = 0; k < usize; ++k) {
+				expect_true(*((unsigned char *)p + k) == 0, "");
+			}
+		}
+		if (j == 0) {
+			expect_true(PAGE_ALIGNED(p), "");
+			continue;
+		}
+		assert(i > 0);
+		void *q = ptrs[i - 1];
+		bool adjacent = (uintptr_t)p > (uintptr_t)q
+		    && (size_t)((uintptr_t)p - (uintptr_t)q) == usize;
+		if (config_prof && opt_prof) {
+			if (adjacent) {
+				expect_false(prof_sampled(tsd, p)
+				    || prof_sampled(tsd, q), "");
+			} else {
+				expect_true(prof_sampled(tsd, p)
+				    || prof_sampled(tsd, q), "");
+				expect_true(PAGE_ALIGNED(p), "");
+				j = 0;
+			}
+		} else {
+			expect_true(adjacent, "");
+		}
+	}
+}
+
+static void
+release_batch(void **ptrs, size_t batch, size_t size) {
+	for (size_t i = 0; i < batch; ++i) {
+		sdallocx(ptrs[i], size, 0);
+	}
+}
+
+static void
+test_wrapper(size_t size, size_t alignment, bool zero, unsigned arena_flag) {
+	tsd_t *tsd = tsd_fetch();
+	assert(tsd != NULL);
+	const size_t usize =
+	    (alignment != 0 ? sz_sa2u(size, alignment) : sz_s2u(size));
+	const szind_t ind = sz_size2index(usize);
+	const bin_info_t *bin_info = &bin_infos[ind];
+	const unsigned nregs = bin_info->nregs;
+	assert(nregs > 0);
+	arena_t *arena;
+	if (arena_flag != 0) {
+		arena = arena_get(tsd_tsdn(tsd), MALLOCX_ARENA_GET(arena_flag),
+		    false);
+	} else {
+		arena = arena_choose(tsd, NULL);
+	}
+	assert(arena != NULL);
+	bin_t *bin = arena_bin_choose(tsd_tsdn(tsd), arena, ind, NULL);
+	assert(bin != NULL);
+	int flags = arena_flag;
+	if (alignment != 0) {
+		flags |= MALLOCX_ALIGN(alignment);
+	}
+	if (zero) {
+		flags |= MALLOCX_ZERO;
+	}
+
+	/*
+	 * Allocate for the purpose of bootstrapping arena_tdata, so that the
+	 * change in bin stats won't contaminate the stats to be verified below.
+	 */
+	void *p = mallocx(size, flags | MALLOCX_TCACHE_NONE);
+
+	for (size_t i = 0; i < 4; ++i) {
+		size_t base = 0;
+		if (i == 1) {
+			base = nregs;
+		} else if (i == 2) {
+			base = nregs * 2;
+		} else if (i == 3) {
+			base = (1 << 16);
+		}
+		for (int j = -1; j <= 1; ++j) {
+			if (base == 0 && j == -1) {
+				continue;
+			}
+			size_t batch = base + (size_t)j;
+			assert(batch < BATCH_MAX);
+			bin_stats_t stats_before, stats_after;
+			memcpy(&stats_before, &bin->stats, sizeof(bin_stats_t));
+			size_t filled = batch_alloc(ptrs, batch, size, flags);
+			assert_zu_eq(filled, batch, "");
+			memcpy(&stats_after, &bin->stats, sizeof(bin_stats_t));
+			verify_stats(&stats_before, &stats_after, batch, nregs);
+			verify_batch(tsd, ptrs, batch, usize, zero, arena,
+			    nregs);
+			release_batch(ptrs, batch, usize);
+		}
+	}
+
+	free(p);
+}
+
+TEST_BEGIN(test_batch_alloc) {
+	test_wrapper(11, 0, false, 0);
+}
+TEST_END
+
+TEST_BEGIN(test_batch_alloc_zero) {
+	test_wrapper(11, 0, true, 0);
+}
+TEST_END
+
+TEST_BEGIN(test_batch_alloc_aligned) {
+	test_wrapper(7, 16, false, 0);
+}
+TEST_END
+
+TEST_BEGIN(test_batch_alloc_manual_arena) {
+	unsigned arena_ind;
+	size_t len_unsigned = sizeof(unsigned);
+	assert_d_eq(mallctl("arenas.create", &arena_ind, &len_unsigned, NULL,
+	    0), 0, "");
+	test_wrapper(11, 0, false, MALLOCX_ARENA(arena_ind));
+}
+TEST_END
+
+TEST_BEGIN(test_batch_alloc_fallback) {
+	const size_t size = SC_LARGE_MINCLASS;
+	for (size_t batch = 0; batch < 4; ++batch) {
+		assert(batch < BATCH_MAX);
+		size_t filled = batch_alloc(ptrs, batch, size, 0);
+		assert_zu_eq(filled, batch, "");
+		release_batch(ptrs, batch, size);
+	}
+}
+TEST_END
+
+int
+main(void) {
+	return test(
+	    test_batch_alloc,
+	    test_batch_alloc_zero,
+	    test_batch_alloc_aligned,
+	    test_batch_alloc_manual_arena,
+	    test_batch_alloc_fallback);
+}

test/unit/batch_alloc.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+export MALLOC_CONF="tcache_gc_incr_bytes:2147483648"

test/unit/batch_alloc_prof.c

@@ -0,0 +1 @@
+#include "batch_alloc.c"

test/unit/batch_alloc_prof.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+export MALLOC_CONF="prof:true,lg_prof_sample:14"