If it's not prepared to free unref page, the pcp page migratetype is
unset. Thus We will get rubbish from get_pcppage_migratetype() and
might list_del &page->lru again after it's already deleted from the
list leading to grumble about data corruption.
Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: Miaohe Lin <[email protected]>
---
mm/page_alloc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7bb79e959ab4..d87b7e6e9e6b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3415,8 +3415,10 @@ void free_unref_page_list(struct list_head *list)
/* Prepare pages for freeing */
list_for_each_entry_safe(page, next, list, lru) {
pfn = page_to_pfn(page);
- if (!free_unref_page_prepare(page, pfn, 0))
+ if (!free_unref_page_prepare(page, pfn, 0)) {
list_del(&page->lru);
+ continue;
+ }
/*
* Free isolated pages directly to the allocator, see
--
2.23.0
On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
> If it's not prepared to free unref page, the pcp page migratetype is
> unset. Thus We will get rubbish from get_pcppage_migratetype() and
> might list_del &page->lru again after it's already deleted from the
> list leading to grumble about data corruption.
>
> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
> Signed-off-by: Miaohe Lin <[email protected]>
Acked-by: Mel Gorman <[email protected]>
This fix is fairly important. Take this patch out and send it on its own
so it gets picked up relatively quickly. It does not belong in a series
that is mostly cosmetic cleanups.
--
Mel Gorman
SUSE Labs
On 31.08.21 15:43, Mel Gorman wrote:
> On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
>> If it's not prepared to free unref page, the pcp page migratetype is
>> unset. Thus We will get rubbish from get_pcppage_migratetype() and
>> might list_del &page->lru again after it's already deleted from the
>> list leading to grumble about data corruption.
>>
>> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>> Signed-off-by: Miaohe Lin <[email protected]>
>
> Acked-by: Mel Gorman <[email protected]>
>
> This fix is fairly important. Take this patch out and send it on its own
> so it gets picked up relatively quickly. It does not belong in a series
> that is mostly cosmetic cleanups.
I think the commit id is wrong. Shouldn't that be
df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with
zone->lock")
?
--
Thanks,
David / dhildenb
On 8/31/21 15:43, Mel Gorman wrote:
> On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
>> If it's not prepared to free unref page, the pcp page migratetype is
>> unset. Thus We will get rubbish from get_pcppage_migratetype() and
>> might list_del &page->lru again after it's already deleted from the
>> list leading to grumble about data corruption.
>>
>> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>> Signed-off-by: Miaohe Lin <[email protected]>
>
> Acked-by: Mel Gorman <[email protected]>
>
> This fix is fairly important. Take this patch out and send it on its own
> so it gets picked up relatively quickly. It does not belong in a series
> that is mostly cosmetic cleanups.
Also Cc: stable, please.
On 2021/8/31 22:23, David Hildenbrand wrote:
> On 31.08.21 15:43, Mel Gorman wrote:
>> On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
>>> If it's not prepared to free unref page, the pcp page migratetype is
>>> unset. Thus We will get rubbish from get_pcppage_migratetype() and
>>> might list_del &page->lru again after it's already deleted from the
>>> list leading to grumble about data corruption.
>>>
>>> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>>> Signed-off-by: Miaohe Lin <[email protected]>
>>
>> Acked-by: Mel Gorman <[email protected]>
>>
>> This fix is fairly important. Take this patch out and send it on its own
>> so it gets picked up relatively quickly. It does not belong in a series
>> that is mostly cosmetic cleanups.
>
> I think the commit id is wrong. Shouldn't that be
>
> df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>
> ?
>
Many thanks for pointing this out.
I used to save the git log in a file to make life easier. But it seems this leads
to the old commit id above.
commit 3dcbe270d8ec57e534f5c605279cdc3ceb1f044a
Author: Mel Gorman <[email protected]>
Date: Fri Jun 4 14:20:03 2021 +1000
mm/page_alloc: avoid conflating IRQs disabled with zone->lock
git name-rev 3dcbe270d8ec
3dcbe270d8ec tags/next-20210604~2^2~196
vs
commit df1acc856923c0a65c28b588585449106c316b71
Author: Mel Gorman <[email protected]>
Date: Mon Jun 28 19:42:00 2021 -0700
mm/page_alloc: avoid conflating IRQs disabled with zone->lock
git name-rev df1acc856923
df1acc856923 tags/next-20210630~2^2~278
Their contents are same but with different commit id. The previous one
could have been git-rebased.
On 2021/9/1 0:34, Vlastimil Babka wrote:
> On 8/31/21 15:43, Mel Gorman wrote:
>> On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
>>> If it's not prepared to free unref page, the pcp page migratetype is
>>> unset. Thus We will get rubbish from get_pcppage_migratetype() and
>>> might list_del &page->lru again after it's already deleted from the
>>> list leading to grumble about data corruption.
>>>
>>> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>>> Signed-off-by: Miaohe Lin <[email protected]>
>>
>> Acked-by: Mel Gorman <[email protected]>
>>
>> This fix is fairly important. Take this patch out and send it on its own
>> so it gets picked up relatively quickly. It does not belong in a series
>> that is mostly cosmetic cleanups.
>
> Also Cc: stable, please.
>
>
Will do. Many thanks for both of your suggestions!
>
> .
>
On 01.09.21 10:02, Miaohe Lin wrote:
> On 2021/8/31 22:23, David Hildenbrand wrote:
>> On 31.08.21 15:43, Mel Gorman wrote:
>>> On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
>>>> If it's not prepared to free unref page, the pcp page migratetype is
>>>> unset. Thus We will get rubbish from get_pcppage_migratetype() and
>>>> might list_del &page->lru again after it's already deleted from the
>>>> list leading to grumble about data corruption.
>>>>
>>>> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>>>> Signed-off-by: Miaohe Lin <[email protected]>
>>>
>>> Acked-by: Mel Gorman <[email protected]>
>>>
>>> This fix is fairly important. Take this patch out and send it on its own
>>> so it gets picked up relatively quickly. It does not belong in a series
>>> that is mostly cosmetic cleanups.
>>
>> I think the commit id is wrong. Shouldn't that be
>>
>> df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>>
>> ?
>>
>
> Many thanks for pointing this out.
>
> I used to save the git log in a file to make life easier. But it seems this leads
> to the old commit id above.
>
> commit 3dcbe270d8ec57e534f5c605279cdc3ceb1f044a
> Author: Mel Gorman <[email protected]>
> Date: Fri Jun 4 14:20:03 2021 +1000
>
> mm/page_alloc: avoid conflating IRQs disabled with zone->lock
>
> git name-rev 3dcbe270d8ec
> 3dcbe270d8ec tags/next-20210604~2^2~196
>
> vs
>
> commit df1acc856923c0a65c28b588585449106c316b71
> Author: Mel Gorman <[email protected]>
> Date: Mon Jun 28 19:42:00 2021 -0700
>
> mm/page_alloc: avoid conflating IRQs disabled with zone->lock
>
> git name-rev df1acc856923
> df1acc856923 tags/next-20210630~2^2~278
>
> Their contents are same but with different commit id. The previous one
> could have been git-rebased.
>
-mm tree commit ids keep changing until patches are upstream. Therefore,
you can observe changing commit ids in -next. Always use the ones from
Linus' tree, they are stable.
--
Thanks,
David / dhildenb
On 2021/9/1 16:10, David Hildenbrand wrote:
> On 01.09.21 10:02, Miaohe Lin wrote:
>> On 2021/8/31 22:23, David Hildenbrand wrote:
>>> On 31.08.21 15:43, Mel Gorman wrote:
>>>> On Mon, Aug 30, 2021 at 10:10:50PM +0800, Miaohe Lin wrote:
>>>>> If it's not prepared to free unref page, the pcp page migratetype is
>>>>> unset. Thus We will get rubbish from get_pcppage_migratetype() and
>>>>> might list_del &page->lru again after it's already deleted from the
>>>>> list leading to grumble about data corruption.
>>>>>
>>>>> Fixes: 3dcbe270d8ec ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>>>>> Signed-off-by: Miaohe Lin <[email protected]>
>>>>
>>>> Acked-by: Mel Gorman <[email protected]>
>>>>
>>>> This fix is fairly important. Take this patch out and send it on its own
>>>> so it gets picked up relatively quickly. It does not belong in a series
>>>> that is mostly cosmetic cleanups.
>>>
>>> I think the commit id is wrong. Shouldn't that be
>>>
>>> df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
>>>
>>> ?
>>>
>>
>> Many thanks for pointing this out.
>>
>> I used to save the git log in a file to make life easier. But it seems this leads
>> to the old commit id above.
>>
>> commit 3dcbe270d8ec57e534f5c605279cdc3ceb1f044a
>> Author: Mel Gorman <[email protected]>
>> Date:?? Fri Jun 4 14:20:03 2021 +1000
>>
>> ???? mm/page_alloc: avoid conflating IRQs disabled with zone->lock
>>
>> git name-rev 3dcbe270d8ec
>> 3dcbe270d8ec tags/next-20210604~2^2~196
>>
>> vs
>>
>> commit df1acc856923c0a65c28b588585449106c316b71
>> Author: Mel Gorman <[email protected]>
>> Date:?? Mon Jun 28 19:42:00 2021 -0700
>>
>> ???? mm/page_alloc: avoid conflating IRQs disabled with zone->lock
>>
>> git name-rev df1acc856923
>> df1acc856923 tags/next-20210630~2^2~278
>>
>> Their contents are same but with different commit id. The previous one
>> could have been git-rebased.
>>
>
> -mm tree commit ids keep changing until patches are upstream. Therefore, you can observe changing commit ids in -next. Always use the ones from Linus' tree, they are stable.
>
Many thanks for your advice, David. :)