Re: [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-07-29 Thread Pankaj Gupta
> Right now, if we have two isolations racing, we might trigger the > WARN_ON_ONCE() and to dump_page(NULL), dereferencing NULL. Let's just > return directly. > > In the future, we might want to report -EAGAIN to the caller instead, as > this could indicate a temporary isolation failure only. > >

Re: [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-07-29 Thread David Hildenbrand
> Am 29.07.2020 um 20:36 schrieb Mike Kravetz : > > On 7/29/20 11:08 AM, David Hildenbrand wrote: >> I have no clue what you mean with "reintroducing this abandoning of >> pageblocks". All this patch is changing is not doing the dump_page() - >> or am I missing something important? > > My

Re: [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-07-29 Thread Mike Kravetz
On 7/29/20 11:08 AM, David Hildenbrand wrote: > I have no clue what you mean with "reintroducing this abandoning of > pageblocks". All this patch is changing is not doing the dump_page() - > or am I missing something important? My apologies!!! I got confused when I saw 'Return -EBUSY' removed

Re: [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-07-29 Thread David Hildenbrand
On 29.07.20 19:31, Mike Kravetz wrote: > On 6/30/20 7:26 AM, David Hildenbrand wrote: >> Right now, if we have two isolations racing, we might trigger the >> WARN_ON_ONCE() and to dump_page(NULL), dereferencing NULL. Let's just >> return directly. > > Just curious, what call path has the

Re: [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-07-29 Thread Mike Kravetz
On 6/30/20 7:26 AM, David Hildenbrand wrote: > Right now, if we have two isolations racing, we might trigger the > WARN_ON_ONCE() and to dump_page(NULL), dereferencing NULL. Let's just > return directly. Just curious, what call path has the WARN_ON_ONCE()/dump_page(NULL)? > > In the future, we

Re: [PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-07-28 Thread Baoquan He
On 06/30/20 at 04:26pm, David Hildenbrand wrote: > Right now, if we have two isolations racing, we might trigger the > WARN_ON_ONCE() and to dump_page(NULL), dereferencing NULL. Let's just > return directly. > > In the future, we might want to report -EAGAIN to the caller instead, as > this could

[PATCH v1 2/6] mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()

2020-06-30 Thread David Hildenbrand
Right now, if we have two isolations racing, we might trigger the WARN_ON_ONCE() and to dump_page(NULL), dereferencing NULL. Let's just return directly. In the future, we might want to report -EAGAIN to the caller instead, as this could indicate a temporary isolation failure only. Cc: Andrew