From: Manfred Spraul <manfred@colorfullife.com>
Maintenance work from Alexander Nyberg <alexn@telia.com>
With the patch applied,
echo "size-4096 0 0 0" > /proc/slabinfo
walks the objects in the size-4096 slab, printing out the calling address
of whoever allocated that object.
It is for leak detection.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
mm/slab.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 43 insertions(+), 3 deletions(-)
diff -puN mm/slab.c~slab-leak-detector mm/slab.c
--- devel/mm/slab.c~slab-leak-detector 2005-08-29 22:54:48.000000000 -0700
+++ devel-akpm/mm/slab.c 2005-08-29 22:54:48.000000000 -0700
@@ -199,7 +199,7 @@
* is less than 512 (PAGE_SIZE<<3), but greater than 256.
*/
-typedef unsigned int kmem_bufctl_t;
+typedef unsigned long kmem_bufctl_t;
#define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
#define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2)
@@ -2341,7 +2341,7 @@ bad:
cachep->name, cachep->num, slabp, slabp->inuse);
for (i=0;i<sizeof(slabp)+cachep->num*sizeof(kmem_bufctl_t);i++) {
if ((i%16)==0)
- printk("\n%03x:", i);
+ printk("\n%04lx:", i);
printk(" %02x", ((unsigned char*)slabp)[i]);
}
printk("\n");
@@ -2493,6 +2493,15 @@ cache_alloc_debugcheck_after(kmem_cache_
*dbg_redzone1(cachep, objp) = RED_ACTIVE;
*dbg_redzone2(cachep, objp) = RED_ACTIVE;
}
+ {
+ int objnr;
+ struct slab *slabp;
+
+ slabp = GET_PAGE_SLAB(virt_to_page(objp));
+
+ objnr = (objp - slabp->s_mem) / cachep->objsize;
+ slab_bufctl(slabp)[objnr] = (unsigned long)caller;
+ }
objp += obj_dbghead(cachep);
if (cachep->ctor && cachep->flags & SLAB_POISON) {
unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR;
@@ -2628,7 +2637,7 @@ static void free_block(kmem_cache_t *cac
check_slabp(cachep, slabp);
-#if DEBUG
+#if 0 /* disabled, not compatible with leak detection */
if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) {
printk(KERN_ERR "slab: double free detected in cache "
"'%s', objp %p\n", cachep->name, objp);
@@ -3507,6 +3516,36 @@ struct seq_operations slabinfo_op = {
.show = s_show,
};
+static void do_dump_slabp(kmem_cache_t *cachep)
+{
+#if DEBUG
+ struct list_head *q;
+ int node;
+
+ check_irq_on();
+ spin_lock_irq(&cachep->spinlock);
+ for_each_online_node(node) {
+ struct kmem_list3 *rl3 = cachep->nodelists[node];
+ spin_lock(&rl3->list_lock);
+
+ list_for_each(q, &rl3->slabs_full) {
+ int i;
+ struct slab *slabp = list_entry(q, struct slab, list);
+
+ for (i = 0; i < cachep->num; i++) {
+ unsigned long sym = slab_bufctl(slabp)[i];
+
+ printk("obj %p/%d: %p", slabp, i, (void *)sym);
+ print_symbol(" <%s>", sym);
+ printk("\n");
+ }
+ }
+ spin_unlock(&rl3->list_lock);
+ }
+ spin_unlock_irq(&cachep->spinlock);
+#endif
+}
+
#define MAX_SLABINFO_WRITE 128
/**
* slabinfo_write - Tuning for the slab allocator
@@ -3547,6 +3586,7 @@ ssize_t slabinfo_write(struct file *file
batchcount < 1 ||
batchcount > limit ||
shared < 0) {
+ do_dump_slabp(cachep);
res = 0;
} else {
res = do_tune_cpucache(cachep, limit,
_