mempool: populate with anonymous memory

Now that we can populate a mempool with any virtual memory,
it is easier to introduce a function to populate a mempool
with memory coming from an anonymous mapping, as it's done
in test-pmd.

The next commit will replace test-pmd anonymous mapping by
this function.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 8be3c74..0ba6c24 100644 (file)
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -40,6 +40,7 @@
 #include <inttypes.h>
 #include <errno.h>
 #include <sys/queue.h>
+#include <sys/mman.h>
 
 #include <rte_common.h>
 #include <rte_log.h>
@@ -591,6 +592,69 @@ rte_mempool_populate_default(struct rte_mempool *mp)
        return ret;
 }
 
+/* return the memory size required for mempool objects in anonymous mem */
+static size_t
+get_anon_size(const struct rte_mempool *mp)
+{
+       size_t size, total_elt_sz, pg_sz, pg_shift;
+
+       pg_sz = getpagesize();
+       pg_shift = rte_bsf32(pg_sz);
+       total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
+       size = rte_mempool_xmem_size(mp->size, total_elt_sz, pg_shift);
+
+       return size;
+}
+
+/* unmap a memory zone mapped by rte_mempool_populate_anon() */
+static void
+rte_mempool_memchunk_anon_free(struct rte_mempool_memhdr *memhdr,
+       void *opaque)
+{
+       munmap(opaque, get_anon_size(memhdr->mp));
+}
+
+/* populate the mempool with an anonymous mapping */
+__rte_unused static int
+rte_mempool_populate_anon(struct rte_mempool *mp)
+{
+       size_t size;
+       int ret;
+       char *addr;
+
+       /* mempool is already populated, error */
+       if (!STAILQ_EMPTY(&mp->mem_list)) {
+               rte_errno = EINVAL;
+               return 0;
+       }
+
+       /* get chunk of virtually continuous memory */
+       size = get_anon_size(mp);
+       addr = mmap(NULL, size, PROT_READ | PROT_WRITE,
+               MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+       if (addr == MAP_FAILED) {
+               rte_errno = errno;
+               return 0;
+       }
+       /* can't use MMAP_LOCKED, it does not exist on BSD */
+       if (mlock(addr, size) < 0) {
+               rte_errno = errno;
+               munmap(addr, size);
+               return 0;
+       }
+
+       ret = rte_mempool_populate_virt(mp, addr, size, getpagesize(),
+               rte_mempool_memchunk_anon_free, addr);
+       if (ret == 0)
+               goto fail;
+
+       return mp->populated_size;
+
+ fail:
+       rte_mempool_free_memchunks(mp);
+       return 0;
+}
+
 /* free a mempool */
 static void
 rte_mempool_free(struct rte_mempool *mp)