From: Wei Yang <richardw.yang@linux.intel.com>
To: David Hildenbrand <david@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>,
n-horiguchi@ah.jp.nec.com, akpm@linux-foundation.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm/memory-failure.c: PageHuge is handled at the beginning of memory_failure
Date: Wed, 20 Nov 2019 08:46:20 +0800 [thread overview]
Message-ID: <20191120004620.GB11061@richard> (raw)
In-Reply-To: <1e61c115-5787-9ef4-a449-2e490c53fca7@redhat.com>
On Tue, Nov 19, 2019 at 01:23:54PM +0100, David Hildenbrand wrote:
>On 18.11.19 09:20, Wei Yang wrote:
>> PageHuge is handled by memory_failure_hugetlb(), so this case could be
>> removed.
>>
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>> ---
>> mm/memory-failure.c | 5 +----
>> 1 file changed, 1 insertion(+), 4 deletions(-)
>>
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index 3151c87dff73..392ac277b17d 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -1359,10 +1359,7 @@ int memory_failure(unsigned long pfn, int flags)
>> * page_remove_rmap() in try_to_unmap_one(). So to determine page status
>> * correctly, we save a copy of the page flags at this time.
>> */
>> - if (PageHuge(p))
>> - page_flags = hpage->flags;
>> - else
>> - page_flags = p->flags;
>> + page_flags = p->flags;
>> /*
>> * unpoison always clear PG_hwpoison inside page lock
>>
>
>I somewhat miss a proper explanation why this is safe to do. We access page
>flags here, so why is it safe to refer to the ones of the sub-page?
>
Hi, David
I think your comment is on this line:
page_flags = p->flags;
Maybe we need to use this:
page_flags = hpage->flags;
And use hpage in the following or even the whole function?
While one thing interesting is not all "compound page" is PageCompound. For
some sub-page, we can't get the correct head. This means we may just check on
the sub-page.
>--
>
>Thanks,
>
>David / dhildenb
--
Wei Yang
Help you, Help me
next prev parent reply other threads:[~2019-11-20 0:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-18 8:20 [PATCH 1/2] mm/memory-failure.c: PageHuge is handled at the beginning of memory_failure Wei Yang
2019-11-18 8:20 ` [PATCH 2/2] mm/memory-failure.c: not necessary to recalculate hpage Wei Yang
2019-11-20 15:07 ` David Hildenbrand
2019-11-21 1:05 ` Wei Yang
2019-12-02 22:28 ` Wei Yang
2019-12-05 15:06 ` David Hildenbrand
2019-12-06 1:48 ` Wei Yang
2020-01-08 12:20 ` David Hildenbrand
2020-01-09 1:58 ` Wei Yang
2019-11-19 12:23 ` [PATCH 1/2] mm/memory-failure.c: PageHuge is handled at the beginning of memory_failure David Hildenbrand
2019-11-20 0:46 ` Wei Yang [this message]
2019-11-20 15:04 ` David Hildenbrand
2019-11-21 1:07 ` Wei Yang
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