From: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
To: Brendan Jackman <brendan.jackman@linux.dev>,
Brendan Jackman <jackmanb@google.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>, Wei Xu <weixugc@google.com>,
Johannes Weiner <hannes@cmpxchg.org>, Zi Yan <ziy@nvidia.com>,
Lorenzo Stoakes <ljs@kernel.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org,
rppt@kernel.org, Sumit Garg <sumit.garg@oss.qualcomm.com>,
derkling@google.com, reijiw@google.com,
Will Deacon <will@kernel.org>,
rientjes@google.com, "Kalyazin, Nikita" <kalyazin@amazon.co.uk>,
patrick.roy@linux.dev, "Itazuri, Takahiro" <itazur@amazon.co.uk>,
Andy Lutomirski <luto@kernel.org>,
David Kaplan <david.kaplan@amd.com>,
Thomas Gleixner <tglx@kernel.org>, Yosry Ahmed <yosry@kernel.org>
Subject: Re: [PATCH v2 19/22] mm/page_alloc: implement __GFP_UNMAPPED allocations
Date: Mon, 15 Jun 2026 15:22:35 +0200 [thread overview]
Message-ID: <17f2f1e7-36ee-4d90-af1c-1fbca6f94025@kernel.org> (raw)
In-Reply-To: <DJ9NAB82KJUF.1G67EXZAJQ3RL@linux.dev>
On 6/15/26 15:08, Brendan Jackman wrote:
> On Mon Jun 15, 2026 at 1:02 PM UTC, Vlastimil Babka (SUSE) wrote:
>>>
>>> Full code:
>>> https://github.com/bjackman/linux/tree/page_alloc-unmapped-2026-06-11
>>>
>>> This makes the regression above (faster OOMs) go away, but it seems like
>>> a pretty blunt approach. But then I'm realising I don't really know why it
>>> matters?
>>
>> You mean, why does it matter that we don't OOM prematurely? I'd say that
>> matters a lot.
>>
>>> The main thing is presumably that we are more likely to
>>> pointlessly attempt compaction or compact more than we need. But in that
>>
>> I don't understand why that would be the case? If compaction thinks our goal
>> is order-0, there won't be any?
>>
>> Or you mean that it doesn't matter that your approach above is blunt, and
>> are talking about the consequences of that blunt approach?
>
> Yeah exactly this - it seems to fix the issue, but I dunno if it's
> cheating. It _feels_ like cheating but I actually don't know what it
> would break - maybe nothing?
Ah ok, now I understand. Will have to check more closely if it can break
something. Maybe Johannes has some insight as he mentioned working on a
similar thing for the defrag mode?
next prev parent reply other threads:[~2026-06-15 13:22 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-20 18:23 [PATCH v2 00/22] mm: Add __GFP_UNMAPPED Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 01/22] x86/mm: split out preallocate_sub_pgd() Brendan Jackman
2026-03-20 19:42 ` Dave Hansen
2026-03-23 11:01 ` Brendan Jackman
2026-03-24 15:27 ` Borislav Petkov
2026-03-25 13:28 ` Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 02/22] x86/mm: Generalize LDT remap into "mm-local region" Brendan Jackman
2026-03-20 19:47 ` Dave Hansen
2026-03-23 12:01 ` Brendan Jackman
2026-03-23 12:57 ` Brendan Jackman
2026-03-25 14:23 ` Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 03/22] x86/tlb: Expose some flush function declarations to modules Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 04/22] mm: Create flags arg for __apply_to_page_range() Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 05/22] mm: Add more flags " Brendan Jackman
2026-03-26 16:14 ` Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 06/22] x86/mm: introduce the mermap Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 07/22] mm: KUnit tests for " Brendan Jackman
2026-03-24 8:00 ` kernel test robot
2026-03-20 18:23 ` [PATCH v2 08/22] mm: introduce for_each_free_list() Brendan Jackman
2026-05-11 13:46 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 09/22] mm/page_alloc: don't overload migratetype in find_suitable_fallback() Brendan Jackman
2026-05-11 13:51 ` Vlastimil Babka (SUSE)
2026-05-11 16:44 ` Brendan Jackman
2026-05-11 16:53 ` Vlastimil Babka (SUSE)
2026-06-12 13:24 ` Gupta, Pankaj
2026-06-12 14:44 ` Brendan Jackman
2026-06-12 15:53 ` Gupta, Pankaj
2026-03-20 18:23 ` [PATCH v2 10/22] mm: introduce freetype_t Brendan Jackman
2026-05-11 15:34 ` Vlastimil Babka (SUSE)
2026-05-11 16:49 ` Brendan Jackman
2026-05-11 16:58 ` Vlastimil Babka (SUSE)
2026-05-11 18:17 ` Vlastimil Babka (SUSE)
2026-05-11 18:26 ` Vlastimil Babka (SUSE)
2026-05-18 0:00 ` Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 11/22] mm: move migratetype definitions to freetype.h Brendan Jackman
2026-05-11 15:35 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 12/22] mm: add definitions for allocating unmapped pages Brendan Jackman
2026-05-11 18:01 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 13/22] mm: rejig pageblock mask definitions Brendan Jackman
2026-05-11 18:07 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 14/22] mm: encode freetype flags in pageblock flags Brendan Jackman
2026-05-11 18:29 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 15/22] mm/page_alloc: remove ifdefs from pindex helpers Brendan Jackman
2026-05-11 18:30 ` Vlastimil Babka (SUSE)
2026-05-12 9:49 ` Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 16/22] mm/page_alloc: separate pcplists by freetype flags Brendan Jackman
2026-05-13 8:46 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 17/22] mm/page_alloc: rename ALLOC_NON_BLOCK back to _HARDER Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 18/22] mm/page_alloc: introduce ALLOC_NOBLOCK Brendan Jackman
2026-05-13 9:43 ` Vlastimil Babka (SUSE)
2026-05-15 13:36 ` Brendan Jackman
2026-05-15 15:52 ` Gregory Price
2026-03-20 18:23 ` [PATCH v2 19/22] mm/page_alloc: implement __GFP_UNMAPPED allocations Brendan Jackman
2026-05-13 15:43 ` Vlastimil Babka (SUSE)
2026-05-15 16:46 ` Brendan Jackman
2026-05-29 15:02 ` Brendan Jackman
2026-06-01 8:50 ` Vlastimil Babka (SUSE)
2026-06-11 14:46 ` Brendan Jackman
2026-06-15 13:02 ` Vlastimil Babka (SUSE)
2026-06-15 13:08 ` Brendan Jackman
2026-06-15 13:22 ` Vlastimil Babka (SUSE) [this message]
2026-06-01 8:59 ` Vlastimil Babka (SUSE)
2026-03-20 18:23 ` [PATCH v2 20/22] mm/page_alloc: implement __GFP_UNMAPPED|__GFP_ZERO allocations Brendan Jackman
2026-05-13 17:00 ` Vlastimil Babka (SUSE)
2026-05-15 16:50 ` Brendan Jackman
2026-06-17 11:32 ` Gupta, Pankaj
2026-06-17 15:56 ` Brendan Jackman
2026-06-17 16:48 ` Gupta, Pankaj
2026-03-20 18:23 ` [PATCH v2 21/22] mm: Minimal KUnit tests for some new page_alloc logic Brendan Jackman
2026-03-20 18:23 ` [PATCH v2 22/22] mm/secretmem: Use __GFP_UNMAPPED when available Brendan Jackman
2026-03-31 14:40 ` Brendan Jackman
2026-05-13 16:17 ` [PATCH v2 00/22] mm: Add __GFP_UNMAPPED Gregory Price
2026-05-13 17:14 ` Brendan Jackman
2026-05-13 17:28 ` Gregory Price
2026-05-13 17:38 ` Vlastimil Babka (SUSE)
2026-05-13 17:59 ` Gregory Price
2026-05-15 9:31 ` Brendan Jackman
2026-05-15 16:04 ` Gregory Price
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