Message-ID: <1cb12058-f59e-1433-6ba6-f500be250996@quicinc.com>
Date:   Wed, 15 Mar 2023 21:23:51 +0530
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Subject: Re: [PATCH] ring-buffer: remove obsolete comment for
 free_buffer_page()
Content-Language: en-US
From:   Mukesh Ojha <quic_mojha@quicinc.com>
To:     Vlastimil Babka <vbabka@suse.cz>,
        Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Ingo Molnar <mingo@elte.hu>
CC:     <linux-trace-kernel@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <patches@lists.linux.dev>,
        Mike Rapoport <mike.rapoport@gmail.com>
References: <20230315142446.27040-1-vbabka@suse.cz>
 <72de48c7-014d-80ac-51e9-ba22450f1d5b@quicinc.com>
In-Reply-To: <72de48c7-014d-80ac-51e9-ba22450f1d5b@quicinc.com>
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On 3/15/2023 9:21 PM, Mukesh Ojha wrote:
> 
> 
> On 3/15/2023 7:54 PM, Vlastimil Babka wrote:
>> The comment refers to mm/slob.o which is being removed. It comes from

nit: mm/slob.c

-- Mukesh

> 
> 
>> commit ed56829cb319 ("ring_buffer: reset buffer page when freeing") and
>> according to Steven the borrowed code was a page mapcount and mapping
>> reset, which was later removed by commit e4c2ce82ca27 ("ring_buffer:
>> allocate buffer page pointer"). Thus the comment is not accurate anyway,
>> remove it.
>>
>> Reported-by: Mike Rapoport <mike.rapoport@gmail.com>
>> Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
>> Fixes: e4c2ce82ca27 ("ring_buffer: allocate buffer page pointer")
>> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
>> ---
>>   kernel/trace/ring_buffer.c | 4 ----
>>   1 file changed, 4 deletions(-)
>>
>> diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
>> index af50d931b020..c6f47b6cfd5f 100644
>> --- a/kernel/trace/ring_buffer.c
>> +++ b/kernel/trace/ring_buffer.c
>> @@ -354,10 +354,6 @@ static void rb_init_page(struct buffer_data_page 
>> *bpage)
>>       local_set(&bpage->commit, 0);
>>   }
>> -/*
>> - * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
>> - * this issue out.
>> - */
> 
> Thanks for the clean up.
> 
> Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
> 
> -- Mukesh
> 
>>   static void free_buffer_page(struct buffer_page *bpage)
>>   {
>>       free_page((unsigned long)bpage->page);