From 8ea9fb921bc68376081a9db410cf1d6afa0c6fb9 Mon Sep 17 00:00:00 2001 From: Oliver Glitta Date: Fri, 21 May 2021 14:11:25 +0200 Subject: 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: Oliver Glitta Signed-off-by: Vlastimil Babka Reviewed-and-tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> --- mm/slub.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) (limited to 'mm/slub.c') diff --git a/mm/slub.c b/mm/slub.c index 98c1450c23f0..f2e550e1adf0 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -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"); } -- cgit v1.2.3