diff mbox series

[1/5] mm/slub: move struct track init out of set_track()

Message ID 20220225180318.20594-2-vbabka@suse.cz (mailing list archive)
State New
Headers show
Series SLUB debugfs improvements based on stackdepot | expand

Commit Message

Vlastimil Babka Feb. 25, 2022, 6:03 p.m. UTC
set_track() either zeroes out the struct track or fills it, depending on
the addr parameter. This is unnecessary as there's only one place that
calls it for the initialization - init_tracking(). We can simply do the
zeroing there, with a single memset() that covers both TRACK_ALLOC and
TRACK_FREE as they are adjacent.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
 mm/slub.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

Comments

Hyeonggon Yoo Feb. 26, 2022, 10:41 a.m. UTC | #1
On Fri, Feb 25, 2022 at 07:03:14PM +0100, Vlastimil Babka wrote:
> set_track() either zeroes out the struct track or fills it, depending on
> the addr parameter. This is unnecessary as there's only one place that
> calls it for the initialization - init_tracking(). We can simply do the
> zeroing there, with a single memset() that covers both TRACK_ALLOC and
> TRACK_FREE as they are adjacent.
> 
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> ---
>  mm/slub.c | 32 +++++++++++++++-----------------
>  1 file changed, 15 insertions(+), 17 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 261474092e43..1fc451f4fe62 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -729,34 +729,32 @@ static void set_track(struct kmem_cache *s, void *object,
>  {
>  	struct track *p = get_track(s, object, alloc);
>  
> -	if (addr) {
>  #ifdef CONFIG_STACKTRACE
> -		unsigned int nr_entries;
> +	unsigned int nr_entries;
>  
> -		metadata_access_enable();
> -		nr_entries = stack_trace_save(kasan_reset_tag(p->addrs),
> -					      TRACK_ADDRS_COUNT, 3);
> -		metadata_access_disable();
> +	metadata_access_enable();
> +	nr_entries = stack_trace_save(kasan_reset_tag(p->addrs),
> +				      TRACK_ADDRS_COUNT, 3);
> +	metadata_access_disable();
>  
> -		if (nr_entries < TRACK_ADDRS_COUNT)
> -			p->addrs[nr_entries] = 0;
> +	if (nr_entries < TRACK_ADDRS_COUNT)
> +		p->addrs[nr_entries] = 0;
>  #endif
> -		p->addr = addr;
> -		p->cpu = smp_processor_id();
> -		p->pid = current->pid;
> -		p->when = jiffies;
> -	} else {
> -		memset(p, 0, sizeof(struct track));
> -	}
> +	p->addr = addr;
> +	p->cpu = smp_processor_id();
> +	p->pid = current->pid;
> +	p->when = jiffies;
>  }
>  
>  static void init_tracking(struct kmem_cache *s, void *object)
>  {
> +	struct track *p;
> +
>  	if (!(s->flags & SLAB_STORE_USER))
>  		return;
>  
> -	set_track(s, object, TRACK_FREE, 0UL);
> -	set_track(s, object, TRACK_ALLOC, 0UL);
> +	p = get_track(s, object, TRACK_ALLOC);
> +	memset(p, 0, 2*sizeof(struct track));
>  }
>

Looks good.
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>

And works nicely.
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>

>  static void print_track(const char *s, struct track *t, unsigned long pr_time)
> -- 
> 2.35.1
> 
>
diff mbox series

Patch

diff --git a/mm/slub.c b/mm/slub.c
index 261474092e43..1fc451f4fe62 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -729,34 +729,32 @@  static void set_track(struct kmem_cache *s, void *object,
 {
 	struct track *p = get_track(s, object, alloc);
 
-	if (addr) {
 #ifdef CONFIG_STACKTRACE
-		unsigned int nr_entries;
+	unsigned int nr_entries;
 
-		metadata_access_enable();
-		nr_entries = stack_trace_save(kasan_reset_tag(p->addrs),
-					      TRACK_ADDRS_COUNT, 3);
-		metadata_access_disable();
+	metadata_access_enable();
+	nr_entries = stack_trace_save(kasan_reset_tag(p->addrs),
+				      TRACK_ADDRS_COUNT, 3);
+	metadata_access_disable();
 
-		if (nr_entries < TRACK_ADDRS_COUNT)
-			p->addrs[nr_entries] = 0;
+	if (nr_entries < TRACK_ADDRS_COUNT)
+		p->addrs[nr_entries] = 0;
 #endif
-		p->addr = addr;
-		p->cpu = smp_processor_id();
-		p->pid = current->pid;
-		p->when = jiffies;
-	} else {
-		memset(p, 0, sizeof(struct track));
-	}
+	p->addr = addr;
+	p->cpu = smp_processor_id();
+	p->pid = current->pid;
+	p->when = jiffies;
 }
 
 static void init_tracking(struct kmem_cache *s, void *object)
 {
+	struct track *p;
+
 	if (!(s->flags & SLAB_STORE_USER))
 		return;
 
-	set_track(s, object, TRACK_FREE, 0UL);
-	set_track(s, object, TRACK_ALLOC, 0UL);
+	p = get_track(s, object, TRACK_ALLOC);
+	memset(p, 0, 2*sizeof(struct track));
 }
 
 static void print_track(const char *s, struct track *t, unsigned long pr_time)