Commit 8ea9fb92 authored by Oliver Glitta's avatar Oliver Glitta Committed by Vlastimil Babka
Browse files

mm/slub: distinguish and print stack traces in debugfs files 



Aggregate objects in slub cache by unique stack trace in addition to
caller address when producing contents of debugfs files alloc_traces and
free_traces in debugfs. Also add the stack traces to the debugfs output.
This makes it much more useful to e.g. debug memory leaks.

Signed-off-by: default avatarOliver Glitta <glittao@gmail.com>
Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-and-tested-by: default avatarHyeonggon Yoo <42.hyeyoo@gmail.com>
parent 5cf909c5

mm/slub.c

+26 −2
Original line number Diff line number Diff line
@@ -5064,6 +5064,7 @@ EXPORT_SYMBOL(validate_slab_cache); 
 */



struct location {

	depot_stack_handle_t handle;

	unsigned long count;

	unsigned long addr;

	long long sum_time;
@@ -5116,9 +5117,13 @@ static int add_location(struct loc_track *t, struct kmem_cache *s, 
{

	long start, end, pos;

	struct location *l;

	unsigned long caddr;

	unsigned long caddr, chandle;

	unsigned long age = jiffies - track->when;

	depot_stack_handle_t handle = 0;



#ifdef CONFIG_STACKDEPOT

	handle = READ_ONCE(track->handle);

#endif

	start = -1;

	end = t->count;
@@ -5133,7 +5138,8 @@ static int add_location(struct loc_track *t, struct kmem_cache *s, 
			break;



		caddr = t->loc[pos].addr;

		if (track->addr == caddr) {

		chandle = t->loc[pos].handle;

		if ((track->addr == caddr) && (handle == chandle)) {



			l = &t->loc[pos];

			l->count++;
@@ -5158,6 +5164,8 @@ static int add_location(struct loc_track *t, struct kmem_cache *s, 


		if (track->addr < caddr)

			end = pos;

		else if (track->addr == caddr && handle < chandle)

			end = pos;

		else

			start = pos;

	}
@@ -5180,6 +5188,7 @@ static int add_location(struct loc_track *t, struct kmem_cache *s, 
	l->max_time = age;

	l->min_pid = track->pid;

	l->max_pid = track->pid;

	l->handle = handle;

	cpumask_clear(to_cpumask(l->cpus));

	cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));

	nodes_clear(l->nodes);
@@ -6089,6 +6098,21 @@ static int slab_debugfs_show(struct seq_file *seq, void *v) 
			seq_printf(seq, " nodes=%*pbl",

				 nodemask_pr_args(&l->nodes));



#ifdef CONFIG_STACKDEPOT

		{

			depot_stack_handle_t handle;

			unsigned long *entries;

			unsigned int nr_entries, j;



			handle = READ_ONCE(l->handle);

			if (handle) {

				nr_entries = stack_depot_fetch(handle, &entries);

				seq_puts(seq, "\n");

				for (j = 0; j < nr_entries; j++)

					seq_printf(seq, "        %pS\n", (void *)entries[j]);

			}

		}

#endif

		seq_puts(seq, "\n");

	}