[dpdk-dev] [PATCH 20/41] eal: add backend support for contiguous allocation

[Anatoly Burakov <anatoly.burakov@intel.com>]

No major changes, just add some checks in a few key places, and
a new parameter to pass around.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_eal/common/eal_common_memzone.c |  20 +++---
 lib/librte_eal/common/malloc_elem.c        | 101 ++++++++++++++++++++++-------
 lib/librte_eal/common/malloc_elem.h        |   4 +-
 lib/librte_eal/common/malloc_heap.c        |  57 ++++++++++------
 lib/librte_eal/common/malloc_heap.h        |   4 +-
 lib/librte_eal/common/rte_malloc.c         |   6 +-
 6 files changed, 134 insertions(+), 58 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_memzone.c b/lib/librte_eal/common/eal_common_memzone.c
index 718dee8..75c7dd9 100644
--- a/lib/librte_eal/common/eal_common_memzone.c
+++ b/lib/librte_eal/common/eal_common_memzone.c
@@ -98,7 +98,8 @@ find_heap_max_free_elem(int *s, unsigned align)
 
 static const struct rte_memzone *
 memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
-		int socket_id, unsigned flags, unsigned align, unsigned bound)
+		int socket_id, unsigned int flags, unsigned int align,
+		unsigned int bound, bool contig)
 {
 	struct rte_memzone *mz;
 	struct rte_mem_config *mcfg;
@@ -182,7 +183,7 @@ memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
 
 	/* allocate memory on heap */
 	void *mz_addr = malloc_heap_alloc(NULL, requested_len, socket_id, flags,
-			align, bound);
+			align, bound, contig);
 
 	if (mz_addr == NULL) {
 		rte_errno = ENOMEM;
@@ -215,9 +216,9 @@ memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
 }
 
 static const struct rte_memzone *
-rte_memzone_reserve_thread_safe(const char *name, size_t len,
-				int socket_id, unsigned flags, unsigned align,
-				unsigned bound)
+rte_memzone_reserve_thread_safe(const char *name, size_t len, int socket_id,
+		unsigned int flags, unsigned int align, unsigned int bound,
+		bool contig)
 {
 	struct rte_mem_config *mcfg;
 	const struct rte_memzone *mz = NULL;
@@ -228,7 +229,7 @@ rte_memzone_reserve_thread_safe(const char *name, size_t len,
 	rte_rwlock_write_lock(&mcfg->mlock);
 
 	mz = memzone_reserve_aligned_thread_unsafe(
-		name, len, socket_id, flags, align, bound);
+		name, len, socket_id, flags, align, bound, contig);
 
 	rte_rwlock_write_unlock(&mcfg->mlock);
 
@@ -245,7 +246,7 @@ rte_memzone_reserve_bounded(const char *name, size_t len, int socket_id,
 			    unsigned flags, unsigned align, unsigned bound)
 {
 	return rte_memzone_reserve_thread_safe(name, len, socket_id, flags,
-					       align, bound);
+					       align, bound, false);
 }
 
 /*
@@ -257,7 +258,7 @@ rte_memzone_reserve_aligned(const char *name, size_t len, int socket_id,
 			    unsigned flags, unsigned align)
 {
 	return rte_memzone_reserve_thread_safe(name, len, socket_id, flags,
-					       align, 0);
+					       align, 0, false);
 }
 
 /*
@@ -269,7 +270,8 @@ rte_memzone_reserve(const char *name, size_t len, int socket_id,
 		    unsigned flags)
 {
 	return rte_memzone_reserve_thread_safe(name, len, socket_id,
-					       flags, RTE_CACHE_LINE_SIZE, 0);
+					       flags, RTE_CACHE_LINE_SIZE, 0,
+					       false);
 }
 
 int
diff --git a/lib/librte_eal/common/malloc_elem.c b/lib/librte_eal/common/malloc_elem.c
index eabad66..d2dba35 100644
--- a/lib/librte_eal/common/malloc_elem.c
+++ b/lib/librte_eal/common/malloc_elem.c
@@ -17,6 +17,7 @@
 #include <rte_common.h>
 #include <rte_spinlock.h>
 
+#include "eal_memalloc.h"
 #include "malloc_elem.h"
 #include "malloc_heap.h"
 
@@ -94,33 +95,88 @@ malloc_elem_insert(struct malloc_elem *elem)
 }
 
 /*
+ * Attempt to find enough physically contiguous memory in this block to store
+ * our data. Assume that element has at least enough space to fit in the data,
+ * so we just check the page addresses.
+ */
+static bool
+elem_check_phys_contig(struct rte_memseg_list *msl, void *start, size_t size)
+{
+	uint64_t page_sz;
+	void *aligned_start, *end, *aligned_end;
+	size_t aligned_len;
+
+	/* figure out how many pages we need to fit in current data */
+	page_sz = msl->hugepage_sz;
+	aligned_start = RTE_PTR_ALIGN_FLOOR(start, page_sz);
+	end = RTE_PTR_ADD(start, size);
+	aligned_end = RTE_PTR_ALIGN_CEIL(end, page_sz);
+
+	aligned_len = RTE_PTR_DIFF(aligned_end, aligned_start);
+
+	return eal_memalloc_is_contig(msl, aligned_start, aligned_len);
+}
+
+/*
  * calculate the starting point of where data of the requested size
  * and alignment would fit in the current element. If the data doesn't
  * fit, return NULL.
  */
 static void *
 elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align,
-		size_t bound)
+		size_t bound, bool contig)
 {
-	const size_t bmask = ~(bound - 1);
-	uintptr_t end_pt = (uintptr_t)elem +
-			elem->size - MALLOC_ELEM_TRAILER_LEN;
-	uintptr_t new_data_start = RTE_ALIGN_FLOOR((end_pt - size), align);
-	uintptr_t new_elem_start;
-
-	/* check boundary */
-	if ((new_data_start & bmask) != ((end_pt - 1) & bmask)) {
-		end_pt = RTE_ALIGN_FLOOR(end_pt, bound);
-		new_data_start = RTE_ALIGN_FLOOR((end_pt - size), align);
-		end_pt = new_data_start + size;
-		if (((end_pt - 1) & bmask) != (new_data_start & bmask))
-			return NULL;
-	}
+	size_t elem_size = elem->size;
 
-	new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
+	/*
+	 * we're allocating from the end, so adjust the size of element by page
+	 * size each time
+	 */
+	while (elem_size >= size) {
+		const size_t bmask = ~(bound - 1);
+		uintptr_t end_pt = (uintptr_t)elem +
+				elem_size - MALLOC_ELEM_TRAILER_LEN;
+		uintptr_t new_data_start = RTE_ALIGN_FLOOR((end_pt - size),
+				align);
+		uintptr_t new_elem_start;
+
+		/* check boundary */
+		if ((new_data_start & bmask) != ((end_pt - 1) & bmask)) {
+			end_pt = RTE_ALIGN_FLOOR(end_pt, bound);
+			new_data_start = RTE_ALIGN_FLOOR((end_pt - size),
+					align);
+			end_pt = new_data_start + size;
+
+			if (((end_pt - 1) & bmask) != (new_data_start & bmask))
+				return NULL;
+		}
 
-	/* if the new start point is before the exist start, it won't fit */
-	return (new_elem_start < (uintptr_t)elem) ? NULL : (void *)new_elem_start;
+		new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
+
+		/* if the new start point is before the exist start,
+		 * it won't fit
+		 */
+		if (new_elem_start < (uintptr_t)elem)
+			return NULL;
+
+		if (contig) {
+			size_t new_data_size = end_pt - new_data_start;
+
+			/*
+			 * if physical contiguousness was requested and we
+			 * couldn't fit all data into one physically contiguous
+			 * block, try again with lower addresses.
+			 */
+			if (!elem_check_phys_contig(elem->msl,
+					(void *) new_data_start,
+					new_data_size)) {
+				elem_size -= align;
+				continue;
+			}
+		}
+		return (void *) new_elem_start;
+	}
+	return NULL;
 }
 
 /*
@@ -129,9 +185,9 @@ elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align,
  */
 int
 malloc_elem_can_hold(struct malloc_elem *elem, size_t size,	unsigned align,
-		size_t bound)
+		size_t bound, bool contig)
 {
-	return elem_start_pt(elem, size, align, bound) != NULL;
+	return elem_start_pt(elem, size, align, bound, contig) != NULL;
 }
 
 /*
@@ -259,9 +315,10 @@ malloc_elem_free_list_remove(struct malloc_elem *elem)
  */
 struct malloc_elem *
 malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
-		size_t bound)
+		size_t bound, bool contig)
 {
-	struct malloc_elem *new_elem = elem_start_pt(elem, size, align, bound);
+	struct malloc_elem *new_elem = elem_start_pt(elem, size, align, bound,
+			contig);
 	const size_t old_elem_size = (uintptr_t)new_elem - (uintptr_t)elem;
 	const size_t trailer_size = elem->size - old_elem_size - size -
 		MALLOC_ELEM_OVERHEAD;
diff --git a/lib/librte_eal/common/malloc_elem.h b/lib/librte_eal/common/malloc_elem.h
index 6d979d2..798472e 100644
--- a/lib/librte_eal/common/malloc_elem.h
+++ b/lib/librte_eal/common/malloc_elem.h
@@ -123,7 +123,7 @@ malloc_elem_insert(struct malloc_elem *elem);
  */
 int
 malloc_elem_can_hold(struct malloc_elem *elem, size_t size,
-		unsigned align, size_t bound);
+		unsigned int align, size_t bound, bool contig);
 
 /*
  * reserve a block of data in an existing malloc_elem. If the malloc_elem
@@ -131,7 +131,7 @@ malloc_elem_can_hold(struct malloc_elem *elem, size_t size,
  */
 struct malloc_elem *
 malloc_elem_alloc(struct malloc_elem *elem, size_t size,
-		unsigned align, size_t bound);
+		unsigned int align, size_t bound, bool contig);
 
 /*
  * free a malloc_elem block by adding it to the free list. If the
diff --git a/lib/librte_eal/common/malloc_heap.c b/lib/librte_eal/common/malloc_heap.c
index 87dc9ad..984e027 100644
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -94,7 +94,7 @@ malloc_heap_add_memory(struct malloc_heap *heap, struct rte_memseg_list *msl,
  */
 static struct malloc_elem *
 find_suitable_element(struct malloc_heap *heap, size_t size,
-		unsigned flags, size_t align, size_t bound)
+		unsigned int flags, size_t align, size_t bound, bool contig)
 {
 	size_t idx;
 	struct malloc_elem *elem, *alt_elem = NULL;
@@ -103,7 +103,8 @@ find_suitable_element(struct malloc_heap *heap, size_t size,
 			idx < RTE_HEAP_NUM_FREELISTS; idx++) {
 		for (elem = LIST_FIRST(&heap->free_head[idx]);
 				!!elem; elem = LIST_NEXT(elem, free_list)) {
-			if (malloc_elem_can_hold(elem, size, align, bound)) {
+			if (malloc_elem_can_hold(elem, size, align, bound,
+					contig)) {
 				if (check_hugepage_sz(flags,
 						elem->msl->hugepage_sz))
 					return elem;
@@ -127,16 +128,16 @@ find_suitable_element(struct malloc_heap *heap, size_t size,
  */
 static void *
 heap_alloc(struct malloc_heap *heap, const char *type __rte_unused, size_t size,
-		unsigned int flags, size_t align, size_t bound)
+		unsigned int flags, size_t align, size_t bound, bool contig)
 {
 	struct malloc_elem *elem;
 
 	size = RTE_CACHE_LINE_ROUNDUP(size);
 	align = RTE_CACHE_LINE_ROUNDUP(align);
 
-	elem = find_suitable_element(heap, size, flags, align, bound);
+	elem = find_suitable_element(heap, size, flags, align, bound, contig);
 	if (elem != NULL) {
-		elem = malloc_elem_alloc(elem, size, align, bound);
+		elem = malloc_elem_alloc(elem, size, align, bound, contig);
 
 		/* increase heap's count of allocated elements */
 		heap->alloc_count++;
@@ -147,14 +148,15 @@ heap_alloc(struct malloc_heap *heap, const char *type __rte_unused, size_t size,
 
 static int
 try_expand_heap(struct malloc_heap *heap, uint64_t pg_sz, size_t elt_size,
-		int socket, unsigned int flags, size_t align, size_t bound)
+		int socket, unsigned int flags, size_t align, size_t bound,
+		bool contig)
 {
+	size_t map_len, data_start_offset;
 	struct rte_memseg_list *msl;
 	struct rte_memseg **ms;
 	struct malloc_elem *elem;
-	size_t map_len;
 	int i, n_pages, allocd_pages;
-	void *ret, *map_addr;
+	void *ret, *map_addr, *data_start;
 
 	align = RTE_MAX(align, MALLOC_ELEM_HEADER_LEN);
 	map_len = RTE_ALIGN_CEIL(align + elt_size + MALLOC_ELEM_TRAILER_LEN,
@@ -175,11 +177,22 @@ try_expand_heap(struct malloc_heap *heap, uint64_t pg_sz, size_t elt_size,
 	map_addr = ms[0]->addr;
 	msl = rte_mem_virt2memseg_list(map_addr);
 
+	/* check if we wanted contiguous memory but didn't get it */
+	data_start_offset = RTE_ALIGN(MALLOC_ELEM_HEADER_LEN, align);
+	data_start = RTE_PTR_ADD(ms[0]->addr, data_start_offset);
+	if (contig && !eal_memalloc_is_contig(msl, data_start,
+			n_pages * msl->hugepage_sz)) {
+		RTE_LOG(DEBUG, EAL, "%s(): couldn't allocate physically contiguous space\n",
+				__func__);
+		goto free_pages;
+	}
+
 	/* add newly minted memsegs to malloc heap */
 	elem = malloc_heap_add_memory(heap, msl, map_addr, map_len);
 
 	/* try once more, as now we have allocated new memory */
-	ret = find_suitable_element(heap, elt_size, flags, align, bound);
+	ret = find_suitable_element(heap, elt_size, flags, align, bound,
+			contig);
 
 	if (ret == NULL)
 		goto free_elem;
@@ -196,6 +209,7 @@ try_expand_heap(struct malloc_heap *heap, uint64_t pg_sz, size_t elt_size,
 	malloc_elem_hide_region(elem, map_addr, map_len);
 	heap->total_size -= map_len;
 
+free_pages:
 	for (i = 0; i < n_pages; i++)
 		eal_memalloc_free_page(ms[i]);
 free_ms:
@@ -223,7 +237,7 @@ compare_pagesz(const void *a, const void *b)
 
 static int
 alloc_mem_on_socket(size_t size, int socket, unsigned int flags, size_t align,
-		size_t bound)
+		size_t bound, bool contig)
 {
 	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
 	struct malloc_heap *heap = &mcfg->malloc_heaps[socket];
@@ -304,14 +318,14 @@ alloc_mem_on_socket(size_t size, int socket, unsigned int flags, size_t align,
 		 * sizes first, before resorting to best effort allocation.
 		 */
 		if (!try_expand_heap(heap, pg_sz, size, socket, size_flags,
-				align, bound))
+				align, bound, contig))
 			return 0;
 	}
 	if (n_other_pg_sz == 0)
 		return -1;
 
 	/* now, check if we can reserve anything with size hint */
-	ret = find_suitable_element(heap, size, flags, align, bound);
+	ret = find_suitable_element(heap, size, flags, align, bound, contig);
 	if (ret != NULL)
 		return 0;
 
@@ -323,7 +337,7 @@ alloc_mem_on_socket(size_t size, int socket, unsigned int flags, size_t align,
 		uint64_t pg_sz = other_pg_sz[i];
 
 		if (!try_expand_heap(heap, pg_sz, size, socket, flags,
-				align, bound))
+				align, bound, contig))
 			return 0;
 	}
 	return -1;
@@ -332,7 +346,7 @@ alloc_mem_on_socket(size_t size, int socket, unsigned int flags, size_t align,
 /* this will try lower page sizes first */
 static void *
 heap_alloc_on_socket(const char *type, size_t size, int socket,
-		unsigned int flags, size_t align, size_t bound)
+		unsigned int flags, size_t align, size_t bound, bool contig)
 {
 	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
 	struct malloc_heap *heap = &mcfg->malloc_heaps[socket];
@@ -345,7 +359,7 @@ heap_alloc_on_socket(const char *type, size_t size, int socket,
 
 	/* for legacy mode, try once and with all flags */
 	if (internal_config.legacy_mem) {
-		ret = heap_alloc(heap, type, size, flags, align, bound);
+		ret = heap_alloc(heap, type, size, flags, align, bound, contig);
 		goto alloc_unlock;
 	}
 
@@ -354,12 +368,12 @@ heap_alloc_on_socket(const char *type, size_t size, int socket,
 	 * we may still be able to allocate memory from appropriate page sizes,
 	 * we just need to request more memory first.
 	 */
-	ret = heap_alloc(heap, type, size, size_flags, align, bound);
+	ret = heap_alloc(heap, type, size, size_flags, align, bound, contig);
 	if (ret != NULL)
 		goto alloc_unlock;
 
-	if (!alloc_mem_on_socket(size, socket, flags, align, bound)) {
-		ret = heap_alloc(heap, type, size, flags, align, bound);
+	if (!alloc_mem_on_socket(size, socket, flags, align, bound, contig)) {
+		ret = heap_alloc(heap, type, size, flags, align, bound, contig);
 
 		/* this should have succeeded */
 		if (ret == NULL)
@@ -372,7 +386,7 @@ heap_alloc_on_socket(const char *type, size_t size, int socket,
 
 void *
 malloc_heap_alloc(const char *type, size_t size, int socket_arg,
-		unsigned int flags, size_t align, size_t bound)
+		unsigned int flags, size_t align, size_t bound, bool contig)
 {
 	int socket, i;
 	void *ret;
@@ -393,7 +407,8 @@ malloc_heap_alloc(const char *type, size_t size, int socket_arg,
 	if (socket >= RTE_MAX_NUMA_NODES)
 		return NULL;
 
-	ret = heap_alloc_on_socket(type, size, socket, flags, align, bound);
+	ret = heap_alloc_on_socket(type, size, socket, flags, align, bound,
+			contig);
 	if (ret != NULL || socket_arg != SOCKET_ID_ANY)
 		return ret;
 
@@ -402,7 +417,7 @@ malloc_heap_alloc(const char *type, size_t size, int socket_arg,
 		if (i == socket)
 			continue;
 		ret = heap_alloc_on_socket(type, size, i, flags,
-				align, bound);
+				align, bound, contig);
 		if (ret != NULL)
 			return ret;
 	}
diff --git a/lib/librte_eal/common/malloc_heap.h b/lib/librte_eal/common/malloc_heap.h
index 292d578..03b8014 100644
--- a/lib/librte_eal/common/malloc_heap.h
+++ b/lib/librte_eal/common/malloc_heap.h
@@ -5,6 +5,8 @@
 #ifndef MALLOC_HEAP_H_
 #define MALLOC_HEAP_H_
 
+#include <stdbool.h>
+
 #include <rte_malloc.h>
 #include <rte_malloc_heap.h>
 
@@ -25,7 +27,7 @@ malloc_get_numa_socket(void)
 
 void *
 malloc_heap_alloc(const char *type, size_t size, int socket, unsigned int flags,
-		size_t align, size_t bound);
+		size_t align, size_t bound, bool contig);
 
 int
 malloc_heap_free(struct malloc_elem *elem);
diff --git a/lib/librte_eal/common/rte_malloc.c b/lib/librte_eal/common/rte_malloc.c
index b0fe11c..5cd92d1 100644
--- a/lib/librte_eal/common/rte_malloc.c
+++ b/lib/librte_eal/common/rte_malloc.c
@@ -37,7 +37,8 @@ void rte_free(void *addr)
  * Allocate memory on specified heap.
  */
 void *
-rte_malloc_socket(const char *type, size_t size, unsigned align, int socket_arg)
+rte_malloc_socket(const char *type, size_t size, unsigned int align,
+		int socket_arg)
 {
 	/* return NULL if size is 0 or alignment is not power-of-2 */
 	if (size == 0 || (align && !rte_is_power_of_2(align)))
@@ -50,8 +51,7 @@ rte_malloc_socket(const char *type, size_t size, unsigned align, int socket_arg)
 	if (socket_arg >= RTE_MAX_NUMA_NODES)
 		return NULL;
 
-	return malloc_heap_alloc(type, size, socket_arg, 0,
-			align == 0 ? 1 : align, 0);
+	return malloc_heap_alloc(type, size, socket_arg, 0, align, 0, false);
 }
 
 /*
-- 
2.7.4