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Subject: Re: [PATCH v3 2/3] mm, slub: don't combine pr_err with INFO
To:     Yafang Shao <laoar.shao@gmail.com>,
        andriy.shevchenko@linux.intel.com, david@redhat.com,
        willy@infradead.org, cl@linux.com, linmiaohe@huawei.com,
        penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com,
        akpm@linux-foundation.org, pmladek@suse.com, rostedt@goodmis.org,
        sergey.senozhatsky@gmail.com, joe@perches.com
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <20210208101439.55474-1-laoar.shao@gmail.com>
 <20210208101439.55474-3-laoar.shao@gmail.com>
From:   Vlastimil Babka <vbabka@suse.cz>
Message-ID: <af67d20c-ca5a-7506-b009-a31c266c3395@suse.cz>
Date:   Mon, 8 Feb 2021 17:33:25 +0100
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On 2/8/21 11:14 AM, Yafang Shao wrote:
> It is strange to combine "pr_err" with "INFO", so let's remove the
> prefix completely.
> This patch is motivated by David's comment[1].
> 
> - before the patch
> [ 8846.517809] INFO: Slab 0x00000000f42a2c60 objects=33 used=3 fp=0x0000000060d32ca8 flags=0x17ffffc0010200(slab|head)
> 
> - after the patch
> [ 6343.396602] Slab 0x000000004382e02b objects=33 used=3 fp=0x000000009ae06ffc flags=0x17ffffc0010200(slab|head)
> 
> [1]. https://lore.kernel.org/linux-mm/b9c0f2b6-e9b0-0c36-ebdd-2bc684c5a762@redhat.com/#t
> 
> Suggested-by: Vlastimil Babka <vbabka@suse.cz>
> Cc: David Hildenbrand <david@redhat.com>
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/slub.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 87ff086e68a4..2514c37ab4e4 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -612,7 +612,7 @@ static void print_track(const char *s, struct track *t, unsigned long pr_time)
>  	if (!t->addr)
>  		return;
>  
> -	pr_err("INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
> +	pr_err("%s in %pS age=%lu cpu=%u pid=%d\n",
>  	       s, (void *)t->addr, pr_time - t->when, t->cpu, t->pid);
>  #ifdef CONFIG_STACKTRACE
>  	{
> @@ -638,7 +638,7 @@ void print_tracking(struct kmem_cache *s, void *object)
>  
>  static void print_page_info(struct page *page)
>  {
> -	pr_err("INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=%#lx(%pGp)\n",
> +	pr_err("Slab 0x%p objects=%u used=%u fp=0x%p flags=%#lx(%pGp)\n",
>  	       page, page->objects, page->inuse, page->freelist,
>  	       page->flags, &page->flags);
>  
> @@ -695,7 +695,7 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
>  
>  	print_page_info(page);
>  
> -	pr_err("INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
> +	pr_err("Object 0x%p @offset=%tu fp=0x%p\n\n",
>  	       p, p - addr, get_freepointer(s, p));
>  
>  	if (s->flags & SLAB_RED_ZONE)
> @@ -788,7 +788,7 @@ static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
>  		end--;
>  
>  	slab_bug(s, "%s overwritten", what);
> -	pr_err("INFO: 0x%p-0x%p @offset=%tu. First byte 0x%x instead of 0x%x\n",
> +	pr_err("0x%p-0x%p @offset=%tu. First byte 0x%x instead of 0x%x\n",
>  					fault, end - 1, fault - addr,
>  					fault[0], value);
>  	print_trailer(s, page, object);
> @@ -3854,7 +3854,7 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page,
>  	for_each_object(p, s, addr, page->objects) {
>  
>  		if (!test_bit(__obj_to_index(s, addr, p), map)) {
> -			pr_err("INFO: Object 0x%p @offset=%tu\n", p, p - addr);
> +			pr_err("Object 0x%p @offset=%tu\n", p, p - addr);
>  			print_tracking(s, p);
>  		}
>  	}
>