Fix bug in smalloc size calculation

[fio.git] / smalloc.c

diff --git a/smalloc.c b/smalloc.c
index e82ef1da0b59faab23a706db1257808c3fb10bbb..0c7c6df7bdd17992a5fa3c8acb6b53a769621009 100644 (file)
--- a/smalloc.c
+++ b/smalloc.c
@@ -10,9 +10,11 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <limits.h>
+#include <fcntl.h>
 
 #include "mutex.h"
 #include "arch/arch.h"
+#include "os/os.h"
 
 #define SMALLOC_REDZONE                /* define to detect memory corruption */
 
@@ -20,13 +22,14 @@
 #define SMALLOC_BPI    (sizeof(unsigned int) * 8)
 #define SMALLOC_BPL    (SMALLOC_BPB * SMALLOC_BPI)
 
-#define INITIAL_SIZE   1024*1024       /* new pool size */
+#define INITIAL_SIZE   8192*1024       /* new pool size */
 #define MAX_POOLS      128             /* maximum number of pools to setup */
 
 #define SMALLOC_PRE_RED                0xdeadbeefU
 #define SMALLOC_POST_RED       0x5aa55aa5U
 
 unsigned int smalloc_pool_size = INITIAL_SIZE;
+const int int_mask = sizeof(int) - 1;
 
 struct pool {
        struct fio_mutex *lock;                 /* protects this pool */
@@ -35,7 +38,6 @@ struct pool {
        unsigned int free_blocks;               /* free blocks */
        unsigned int nr_blocks;                 /* total blocks */
        unsigned int next_non_full;
-       int fd;                                 /* memory backing fd */
        unsigned int mmap_size;
 };
 
@@ -169,20 +171,15 @@ static void clear_blocks(struct pool *pool, unsigned int pool_idx,
 static int find_next_zero(int word, int start)
 {
        assert(word != -1U);
-       word >>= (start + 1);
-       return ffz(word) + start + 1;
+       word >>= start;
+       return ffz(word) + start;
 }
 
 static int add_pool(struct pool *pool, unsigned int alloc_size)
 {
-       int fd, bitmap_blocks;
-       char file[] = "/tmp/.fio_smalloc.XXXXXX";
+       int bitmap_blocks;
        void *ptr;
 
-       fd = mkstemp(file);
-       if (fd < 0)
-               goto out_close;
-
 #ifdef SMALLOC_REDZONE
        alloc_size += sizeof(unsigned int);
 #endif
@@ -195,16 +192,14 @@ static int add_pool(struct pool *pool, unsigned int alloc_size)
        bitmap_blocks = alloc_size / SMALLOC_BPL;
        alloc_size += bitmap_blocks * sizeof(unsigned int);
        pool->mmap_size = alloc_size;
-       
+
        pool->nr_blocks = bitmap_blocks;
        pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
 
-       if (ftruncate(fd, alloc_size) < 0)
-               goto out_unlink;
-
-       ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+       ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE,
+                       MAP_SHARED | OS_MAP_ANON, -1, 0);
        if (ptr == MAP_FAILED)
-               goto out_unlink;
+               goto out_fail;
 
        memset(ptr, 0, alloc_size);
        pool->map = ptr;
@@ -212,25 +207,14 @@ static int add_pool(struct pool *pool, unsigned int alloc_size)
 
        pool->lock = fio_mutex_init(1);
        if (!pool->lock)
-               goto out_unlink;
-
-       /*
-        * Unlink pool file now. It wont get deleted until the fd is closed,
-        * which happens both for cleanup or unexpected quit. This way we
-        * don't leave temp files around in case of a crash.
-        */
-       unlink(file);
-       pool->fd = fd;
+               goto out_fail;
 
        nr_pools++;
        return 0;
-out_unlink:
+out_fail:
        fprintf(stderr, "smalloc: failed adding pool\n");
        if (pool->map)
                munmap(pool->map, pool->mmap_size);
-       unlink(file);
-out_close:
-       close(fd);
        return 1;
 }
 
@@ -249,7 +233,6 @@ static void cleanup_pool(struct pool *pool)
         * This will also remove the temporary file we used as a backing
         * store, it was already unlinked
         */
-       close(pool->fd);
        munmap(pool->map, pool->mmap_size);
 
        if (pool->lock)
@@ -268,9 +251,19 @@ void scleanup(void)
 }
 
 #ifdef SMALLOC_REDZONE
+static void *postred_ptr(struct block_hdr *hdr)
+{
+       unsigned long ptr;
+
+       ptr = (unsigned long) hdr + hdr->size - sizeof(unsigned int);
+       ptr = (ptr + int_mask) & ~int_mask;
+
+       return (void *) ptr;
+}
+
 static void fill_redzone(struct block_hdr *hdr)
 {
-       unsigned int *postred = (void *) hdr + hdr->size - sizeof(unsigned int);
+       unsigned int *postred = postred_ptr(hdr);
 
        hdr->prered = SMALLOC_PRE_RED;
        *postred = SMALLOC_POST_RED;
@@ -278,7 +271,7 @@ static void fill_redzone(struct block_hdr *hdr)
 
 static void sfree_check_redzone(struct block_hdr *hdr)
 {
-       unsigned int *postred = (void *) hdr + hdr->size - sizeof(unsigned int);
+       unsigned int *postred = postred_ptr(hdr);
 
        if (hdr->prered != SMALLOC_PRE_RED) {
                fprintf(stderr, "smalloc pre redzone destroyed!\n");
@@ -414,8 +407,13 @@ static void *smalloc_pool(struct pool *pool, unsigned int size)
        unsigned int alloc_size = size + sizeof(struct block_hdr);
        void *ptr;
 
+       /*
+        * Round to int alignment, so that the postred pointer will
+        * be naturally aligned as well.
+        */
 #ifdef SMALLOC_REDZONE
        alloc_size += sizeof(unsigned int);
+       alloc_size = (alloc_size + int_mask) & ~int_mask;
 #endif
 
        ptr = __smalloc_pool(pool, alloc_size);