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authorJens Axboe <axboe@kernel.dk>2019-07-31 13:58:44 -0600
committerJens Axboe <axboe@kernel.dk>2019-07-31 13:58:44 -0600
commit23380ef29cdf6eaba8bafaf1c3e51e82610ad5ad (patch)
treef2fc1a64d94a32fcae15274ced68c30aa3b0e67d
parenta15abb450459195ce72d515dc564f07f7726bf5f (diff)
parent554461db6d57df00766e2c4cc7d18f1561d2fa4b (diff)
downloadfio-23380ef29cdf6eaba8bafaf1c3e51e82610ad5ad.tar.gz
fio-23380ef29cdf6eaba8bafaf1c3e51e82610ad5ad.tar.bz2
Merge branch 'smalloc-gc' of https://github.com/vincentkfu/fio
* 'smalloc-gc' of https://github.com/vincentkfu/fio: smalloc: fix garbage collection problem t/stest: make the test more challenging smalloc: print debug info on oom error
-rw-r--r--smalloc.c105
-rw-r--r--smalloc.h1
-rw-r--r--t/stest.c21
3 files changed, 122 insertions, 5 deletions
diff --git a/smalloc.c b/smalloc.c
index a2ad25a0..c97bcbaa 100644
--- a/smalloc.c
+++ b/smalloc.c
@@ -48,6 +48,12 @@ struct block_hdr {
#endif
};
+/*
+ * This suppresses the voluminous potential bitmap printout when
+ * smalloc encounters an OOM error
+ */
+static const bool enable_smalloc_debug = false;
+
static struct pool mp[MAX_POOLS];
static unsigned int nr_pools;
static unsigned int last_pool;
@@ -332,6 +338,17 @@ void sfree(void *ptr)
log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
}
+static unsigned int firstfree(struct pool *pool)
+{
+ unsigned int i;
+
+ for (i = 0; i < pool->nr_blocks; i++)
+ if (pool->bitmap[i] != -1U)
+ return i;
+
+ assert(0);
+}
+
static void *__smalloc_pool(struct pool *pool, size_t size)
{
size_t nr_blocks;
@@ -346,7 +363,14 @@ static void *__smalloc_pool(struct pool *pool, size_t size)
if (nr_blocks > pool->free_blocks)
goto fail;
- i = pool->next_non_full;
+ for (i = pool->next_non_full; pool->bitmap[i] == -1U; i++)
+ if (i == pool->nr_blocks - 1) {
+ i = firstfree(pool);
+ break;
+ }
+
+ pool->next_non_full = i;
+
last_idx = 0;
offset = -1U;
while (i < pool->nr_blocks) {
@@ -354,7 +378,6 @@ static void *__smalloc_pool(struct pool *pool, size_t size)
if (pool->bitmap[i] == -1U) {
i++;
- pool->next_non_full = i;
last_idx = 0;
continue;
}
@@ -387,10 +410,9 @@ fail:
return ret;
}
-static void *smalloc_pool(struct pool *pool, size_t size)
+static size_t size_to_alloc_size(size_t size)
{
size_t alloc_size = size + sizeof(struct block_hdr);
- void *ptr;
/*
* Round to int alignment, so that the postred pointer will
@@ -401,6 +423,14 @@ static void *smalloc_pool(struct pool *pool, size_t size)
alloc_size = (alloc_size + int_mask) & ~int_mask;
#endif
+ return alloc_size;
+}
+
+static void *smalloc_pool(struct pool *pool, size_t size)
+{
+ size_t alloc_size = size_to_alloc_size(size);
+ void *ptr;
+
ptr = __smalloc_pool(pool, alloc_size);
if (ptr) {
struct block_hdr *hdr = ptr;
@@ -415,6 +445,72 @@ static void *smalloc_pool(struct pool *pool, size_t size)
return ptr;
}
+static void smalloc_print_bitmap(struct pool *pool)
+{
+ size_t nr_blocks = pool->nr_blocks;
+ unsigned int *bitmap = pool->bitmap;
+ unsigned int i, j;
+ char *buffer;
+
+ if (!enable_smalloc_debug)
+ return;
+
+ buffer = malloc(SMALLOC_BPI + 1);
+ if (!buffer)
+ return;
+ buffer[SMALLOC_BPI] = '\0';
+
+ for (i = 0; i < nr_blocks; i++) {
+ unsigned int line = bitmap[i];
+
+ /* skip completely full lines */
+ if (line == -1U)
+ continue;
+
+ for (j = 0; j < SMALLOC_BPI; j++)
+ if ((1 << j) & line)
+ buffer[SMALLOC_BPI-1-j] = '1';
+ else
+ buffer[SMALLOC_BPI-1-j] = '0';
+
+ log_err("smalloc: bitmap %5u, %s\n", i, buffer);
+ }
+
+ free(buffer);
+}
+
+void smalloc_debug(size_t size)
+{
+ unsigned int i;
+ size_t alloc_size = size_to_alloc_size(size);
+ size_t alloc_blocks;
+
+ alloc_blocks = size_to_blocks(alloc_size);
+
+ if (size)
+ log_err("smalloc: size = %lu, alloc_size = %lu, blocks = %lu\n",
+ (unsigned long) size, (unsigned long) alloc_size,
+ (unsigned long) alloc_blocks);
+ for (i = 0; i < nr_pools; i++) {
+ log_err("smalloc: pool %u, free/total blocks %u/%u\n", i,
+ (unsigned int) (mp[i].free_blocks),
+ (unsigned int) (mp[i].nr_blocks*sizeof(unsigned int)*8));
+ if (size && mp[i].free_blocks >= alloc_blocks) {
+ void *ptr = smalloc_pool(&mp[i], size);
+ if (ptr) {
+ sfree(ptr);
+ last_pool = i;
+ log_err("smalloc: smalloc_pool %u succeeded\n", i);
+ } else {
+ log_err("smalloc: smalloc_pool %u failed\n", i);
+ log_err("smalloc: next_non_full=%u, nr_blocks=%u\n",
+ (unsigned int) mp[i].next_non_full, (unsigned int) mp[i].nr_blocks);
+ smalloc_print_bitmap(&mp[i]);
+ }
+ }
+ }
+}
+
void *smalloc(size_t size)
{
unsigned int i, end_pool;
@@ -445,6 +541,7 @@ void *smalloc(size_t size)
log_err("smalloc: OOM. Consider using --alloc-size to increase the "
"shared memory available.\n");
+ smalloc_debug(size);
return NULL;
}
diff --git a/smalloc.h b/smalloc.h
index 8df10e6f..1f7716f4 100644
--- a/smalloc.h
+++ b/smalloc.h
@@ -9,6 +9,7 @@ extern void sfree(void *);
extern char *smalloc_strdup(const char *);
extern void sinit(void);
extern void scleanup(void);
+extern void smalloc_debug(size_t);
extern unsigned int smalloc_pool_size;
diff --git a/t/stest.c b/t/stest.c
index b95968f1..515ae5a5 100644
--- a/t/stest.c
+++ b/t/stest.c
@@ -11,11 +11,14 @@
#define MAGIC2 0xf0a1e9b3
#define LOOPS 32
+#define MAXSMALLOC 120*1024*1024UL
+#define LARGESMALLOC 128*1024U
struct elem {
unsigned int magic1;
struct flist_head list;
unsigned int magic2;
+ unsigned int size;
};
static FLIST_HEAD(list);
@@ -25,13 +28,15 @@ static int do_rand_allocs(void)
unsigned int size, nr, rounds = 0;
unsigned long total;
struct elem *e;
+ bool error;
while (rounds++ < LOOPS) {
#ifdef STEST_SEED
srand(MAGIC1);
#endif
+ error = false;
nr = total = 0;
- while (total < 120*1024*1024UL) {
+ while (total < MAXSMALLOC) {
size = 8 * sizeof(struct elem) + (int) (999.0 * (rand() / (RAND_MAX + 1.0)));
e = smalloc(size);
if (!e) {
@@ -40,6 +45,7 @@ static int do_rand_allocs(void)
}
e->magic1 = MAGIC1;
e->magic2 = MAGIC2;
+ e->size = size;
total += size;
flist_add_tail(&e->list, &list);
nr++;
@@ -51,8 +57,20 @@ static int do_rand_allocs(void)
e = flist_entry(list.next, struct elem, list);
assert(e->magic1 == MAGIC1);
assert(e->magic2 == MAGIC2);
+ total -= e->size;
flist_del(&e->list);
sfree(e);
+
+ if (!error) {
+ e = smalloc(LARGESMALLOC);
+ if (!e) {
+ error = true;
+ printf("failure allocating %u bytes at %lu allocated during sfree phase\n",
+ LARGESMALLOC, total);
+ }
+ else
+ sfree(e);
+ }
}
}
@@ -66,6 +84,7 @@ int main(int argc, char *argv[])
debug_init();
do_rand_allocs();
+ smalloc_debug(0); /* free and total blocks should match */
scleanup();
return 0;