On 2022-10-05 06:09, datshan wrote:
From: Chengwen Feng <fengcheng...@huawei.com>
This patch supports backup memory mechanism, the memarea could use
another memarea as a backup.
Maybe it's worth mentioning what backup means already here.
"This patch adds a memarea backup mechanism, where an allocation request
which cannot be met by a certain memarea is deferred to its backup memarea."
I assume they can be nested indefinitely?
Signed-off-by: Chengwen Feng <fengcheng...@huawei.com>
---
doc/guides/prog_guide/memarea_lib.rst | 3 +++
lib/memarea/memarea_private.h | 2 ++
lib/memarea/rte_memarea.c | 22 ++++++++++++++++++++++
lib/memarea/rte_memarea.h | 7 +++++++
4 files changed, 34 insertions(+)
diff --git a/doc/guides/prog_guide/memarea_lib.rst
b/doc/guides/prog_guide/memarea_lib.rst
index c77012fe44..842d35f77a 100644
--- a/doc/guides/prog_guide/memarea_lib.rst
+++ b/doc/guides/prog_guide/memarea_lib.rst
@@ -25,6 +25,9 @@ The main features are as follows:
* It supports MT-safe as long as it's specified at creation time.
+* It provides backup memory mechanism, the memarea could use another memarea
+ as a backup.
+
Library API Overview
--------------------
diff --git a/lib/memarea/memarea_private.h b/lib/memarea/memarea_private.h
index 98406879b9..08735ca81f 100644
--- a/lib/memarea/memarea_private.h
+++ b/lib/memarea/memarea_private.h
@@ -23,11 +23,13 @@ struct rte_memarea {
struct rte_memarea_param init;
rte_spinlock_t lock;
void *area_addr;
+ void *top_addr;
struct memarea_elem_list elem_list;
struct memarea_elem_list free_list;
uint64_t alloc_fails;
uint64_t refcnt_check_fails;
+ uint64_t bak_alloc_fails;
} __rte_cache_aligned;
#endif /* MEMAREA_PRIVATE_H */
diff --git a/lib/memarea/rte_memarea.c b/lib/memarea/rte_memarea.c
index b70830d0bb..f45191aa7f 100644
--- a/lib/memarea/rte_memarea.c
+++ b/lib/memarea/rte_memarea.c
@@ -132,6 +132,7 @@ rte_memarea_create(const struct rte_memarea_param *init)
TAILQ_INIT(&ma->elem_list);
TAILQ_INIT(&ma->free_list);
ma->area_addr = addr;
+ ma->top_addr = (void *)((uintptr_t)addr + init->total_sz - 1);
RTE_PTR_ADD()
elem = addr;
elem->size = init->total_sz - sizeof(struct memarea_elem);
elem->cookie = MEMAREA_FREE_ELEM_COOKIE;
@@ -200,6 +201,15 @@ memarea_add_node(struct rte_memarea *ma, struct
memarea_elem *elem, size_t need_
elem->size = align_size;
}
+static inline void *
+memarea_alloc_backup(struct rte_memarea *ma, size_t size, uint32_t cookie)
+{
+ void *ptr = rte_memarea_alloc(ma->init.bak_memarea, size, cookie);
+ if (unlikely(ptr == NULL))
+ ma->bak_alloc_fails++;
+ return ptr;
+}
+
void *
rte_memarea_alloc(struct rte_memarea *ma, size_t size, uint32_t cookie)
{
@@ -221,6 +231,8 @@ rte_memarea_alloc(struct rte_memarea *ma, size_t size,
uint32_t cookie)
ptr = (void *)((uintptr_t)elem + sizeof(struct memarea_elem));
break;
}
+ if (ptr == NULL && ma->init.bak_memarea != NULL)
Maybe you want an unlikely() around the above, too. I assume using the
backup area is an exceptional case.
+ ptr = memarea_alloc_backup(ma, size, cookie);
if (unlikely(ptr == NULL))
ma->alloc_fails++;
memarea_unlock(ma);
@@ -283,6 +295,12 @@ rte_memarea_update_refcnt(struct rte_memarea *ma, void
*ptr, int16_t value)
return;
memarea_lock(ma);
+ if (ptr < ma->area_addr || ptr > ma->top_addr) {
+ rte_memarea_update_refcnt(ma->init.bak_memarea, ptr, value);
+ memarea_unlock(ma);
+ return;
+ }
+
if (unlikely(elem->refcnt <= 0 || elem->refcnt + value < 0)) {
RTE_LOG(ERR, MEMAREA,
"memarea: %s cookie: 0x%x curr refcnt: %d update refcnt: %d
check fail!\n",
@@ -373,10 +391,14 @@ rte_memarea_dump(struct rte_memarea *ma, FILE *f, bool
dump_all)
fprintf(f, " algorithm: %s\n", memarea_alg_name(ma->init.alg));
fprintf(f, " total-size: 0x%zx\n", ma->init.total_sz);
fprintf(f, " mt-safe: %s\n", ma->init.mt_safe ? "yes" : "no");
+ if (ma->init.bak_memarea)
+ fprintf(f, " backup-memarea-name: %s\n",
ma->init.bak_memarea->init.name);
fprintf(f, " total-regions: %u\n", memarea_elem_list_num(ma));
fprintf(f, " total-free-regions: %u\n", memarea_free_list_num(ma));
fprintf(f, " alloc_fails: %" PRIu64 "\n", ma->alloc_fails);
fprintf(f, " refcnt_check_fails: %" PRIu64 "\n",
ma->refcnt_check_fails);
+ if (ma->init.bak_memarea)
+ fprintf(f, " backup_alloc_fails: %" PRIu64 "\n",
ma->bak_alloc_fails);
if (dump_all)
memarea_dump_all(ma, f);
memarea_unlock(ma);
diff --git a/lib/memarea/rte_memarea.h b/lib/memarea/rte_memarea.h
index 10b8229c64..348febab7f 100644
--- a/lib/memarea/rte_memarea.h
+++ b/lib/memarea/rte_memarea.h
@@ -39,6 +39,9 @@
* specified, all the functions of the memarea API are lock-free, and assume
* to not be invoked in parallel on different logical cores to work on the
* same memarea.
+ * - It provides backup memory mechanism, the memarea could use another memarea
+ * as a backup. It will attempts to allocate object from backup memarea when
+ * the current memarea failed to allocate.
*/
#include <stdbool.h>
@@ -105,6 +108,10 @@ struct rte_memarea_param {
*/
struct rte_memarea *user_memarea;
};
+ /** Backup memarea, which is used to handle the scenario where the
+ * current memarea allocation failure.
+ */
+ struct rte_memarea *bak_memarea;
};
/**
