Messages in this thread |  | | Date | Wed, 20 Nov 2019 08:46:20 +0800 | | From | Wei Yang <> | | Subject | Re: [PATCH 1/2] mm/memory-failure.c: PageHuge is handled at the beginning of memory_failure |
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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
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