linux-kernel - Re: [Patch v2 2/4] mm/page_alloc.c: bad_[reason|flags] is not necessary when PageHWPoison

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Message-ID: <20200120121315.GC18028@richard>
Date:   Mon, 20 Jan 2020 20:13:15 +0800
From:   Wei Yang <richardw.yang@...ux.intel.com>
To:     Anshuman Khandual <anshuman.khandual@....com>
Cc:     Wei Yang <richardw.yang@...ux.intel.com>,
        akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, rientjes@...gle.com
Subject: Re: [Patch v2 2/4] mm/page_alloc.c: bad_[reason|flags] is not
 necessary when PageHWPoison

On Mon, Jan 20, 2020 at 11:58:04AM +0530, Anshuman Khandual wrote:
>
>
>On 01/20/2020 08:34 AM, Wei Yang wrote:
>> Since function returns directly, bad_[reason|flags] is not used any
>> where.
>> 
>> This is a following cleanup for commit e570f56cccd21 ("mm:
>> check_new_page_bad() directly returns in __PG_HWPOISON case")
>> 
>> Signed-off-by: Wei Yang <richardw.yang@...ux.intel.com>
>> Acked-by: David Rientjes <rientjes@...gle.com>
>> ---
>>  mm/page_alloc.c | 2 --
>>  1 file changed, 2 deletions(-)
>> 
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 0cf6218aaba7..a43b9d2482f2 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -2051,8 +2051,6 @@ static void check_new_page_bad(struct page *page)
>>  	if (unlikely(page_ref_count(page) != 0))
>>  		bad_reason = "nonzero _refcount";
>>  	if (unlikely(page->flags & __PG_HWPOISON)) {
>> -		bad_reason = "HWPoisoned (hardware-corrupted)";
>> -		bad_flags = __PG_HWPOISON;
>>  		/* Don't complain about hwpoisoned pages */
>>  		page_mapcount_reset(page); /* remove PageBuddy */
>>  		return;
>
>This bail out condition should be the first in the function
>check_new_page_bad() before evaluating bad_[reason|flags]
>as they will never be used.
>

This is reasonable.

>> 

-- 
Wei Yang
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