Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-12-18 Thread Andrew Morton
On Wed, 18 Dec 2019 18:08:04 +0100 David Hildenbrand wrote: > On 01.12.19 00:21, Andrew Morton wrote: > > On Sun, 27 Oct 2019 23:45:52 +0100 David Hildenbrand > > wrote: > > > >> I think I just found an issue with try_offline_node(). > >> try_offline_node() is pretty much broken already (touc

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-12-18 Thread David Hildenbrand
On 01.12.19 00:21, Andrew Morton wrote: > On Sun, 27 Oct 2019 23:45:52 +0100 David Hildenbrand wrote: > >> I think I just found an issue with try_offline_node(). >> try_offline_node() is pretty much broken already (touches garbage >> memmaps and will not considers mixed NIDs within sections), h

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-12-03 Thread David Hildenbrand
On 03.12.19 16:10, Oscar Salvador wrote: > On Sun, Oct 06, 2019 at 10:56:41AM +0200, David Hildenbrand wrote: >> Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") >> Signed-off-by: David Hildenbrand > > I did not see anything wrong with the taken approach, and makes sense to me.

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-12-03 Thread Oscar Salvador
On Sun, Oct 06, 2019 at 10:56:41AM +0200, David Hildenbrand wrote: > Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") > Signed-off-by: David Hildenbrand I did not see anything wrong with the taken approach, and makes sense to me. The only thing that puzzles me is we seem to not

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-11-30 Thread David Hildenbrand
> Am 01.12.2019 um 00:22 schrieb Andrew Morton : > > On Sun, 27 Oct 2019 23:45:52 +0100 David Hildenbrand > wrote: > >> I think I just found an issue with try_offline_node(). >> try_offline_node() is pretty much broken already (touches garbage >> memmaps and will not considers mixed NIDs

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-11-30 Thread Andrew Morton
On Sun, 27 Oct 2019 23:45:52 +0100 David Hildenbrand wrote: > I think I just found an issue with try_offline_node(). > try_offline_node() is pretty much broken already (touches garbage > memmaps and will not considers mixed NIDs within sections), however, > relies on the node span to look for

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-10-27 Thread David Hildenbrand
On 06.10.19 10:56, David Hildenbrand wrote: We currently try to shrink a single zone when removing memory. We use the zone of the first page of the memory we are removing. If that memmap was never initialized (e.g., memory was never onlined), we will read garbage and can trigger kernel BUGs (due

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-10-14 Thread Andrew Morton
On Mon, 14 Oct 2019 11:39:13 +0200 David Hildenbrand wrote: > > Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") > > @Andrew, can you convert that to > > Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to > zones until online") # visible after d0dc1

Re: [PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-10-14 Thread David Hildenbrand
On 06.10.19 10:56, David Hildenbrand wrote: > We currently try to shrink a single zone when removing memory. We use the > zone of the first page of the memory we are removing. If that memmap was > never initialized (e.g., memory was never onlined), we will read garbage > and can trigger kernel BUGs

[PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory

2019-10-06 Thread David Hildenbrand
We currently try to shrink a single zone when removing memory. We use the zone of the first page of the memory we are removing. If that memmap was never initialized (e.g., memory was never onlined), we will read garbage and can trigger kernel BUGs (due to a stale pointer): :/# [ 23.912993] BUG: