linux-kernel - [PATCH mm-unstable v3 0/3] tweaks for __alloc_pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20260106-thp-thisnode-tweak-v3-0-f5d67c21a193@suse.cz>
Date: Tue, 06 Jan 2026 12:52:35 +0100
From: Vlastimil Babka <vbabka@...e.cz>
To: Andrew Morton <akpm@...ux-foundation.org>, 
 Suren Baghdasaryan <surenb@...gle.com>, Michal Hocko <mhocko@...e.com>, 
 Brendan Jackman <jackmanb@...gle.com>, Johannes Weiner <hannes@...xchg.org>, 
 Zi Yan <ziy@...dia.com>, David Rientjes <rientjes@...gle.com>, 
 David Hildenbrand <david@...nel.org>, 
 Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, 
 "Liam R. Howlett" <Liam.Howlett@...cle.com>, 
 Mike Rapoport <rppt@...nel.org>, Joshua Hahn <joshua.hahnjy@...il.com>, 
 Pedro Falcato <pfalcato@...e.de>
Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org, 
 Vlastimil Babka <vbabka@...e.cz>
Subject: [PATCH mm-unstable v3 0/3] tweaks for __alloc_pages_slowpath()

First non-RFC of the page allocator cleanups on top of the THP
allocation fix:

https://lore.kernel.org/all/20251219-costly-noretry-thisnode-fix-v1-1-e1085a4a0c34@suse.cz/

Rebased to mm-unstable where the fix is included now.

In patch 1, in v1 (where it was patch 2) I have proposed not to attempt
reclaim for costly __GFP_NORETRY allocations at all. Johannes suggested
that we should not change the semantics that much, so now instead we
allow them all (except with __GFP_THISNODE). The main idea that remains
is that we don't decide based on the exact compaction result anymore.

Patch 2 is a cleanup also based on a suggestion from Johannes, and Patch
3 became the obvious next step in that direction. These should be making
no functional changes, while simplifying __alloc_pages_slowpath().

Signed-off-by: Vlastimil Babka <vbabka@...e.cz>
---
Changes in v3:
- Remove RFC tag, rebase to mm-unstable.
- Remove gfp_thisnode_noretry() in Patch 2 (per Joshua).
- Instead add gfp_has_flags() to shorten checking for multiple flags.
- Link to v2: https://patch.msgid.link/20251219-thp-thisnode-tweak-v2-0-0c01f231fd1c@suse.cz

Changes in v2:
- actual THP reclaim fix sent separately
- allow one reclaim attempt for __GFP_NORETRY allocations
- further __alloc_pages_slowpath() cleanups
- Link to v1: https://patch.msgid.link/20251216-thp-thisnode-tweak-v1-0-0e499d13d2eb@suse.cz

---
Vlastimil Babka (3):
      mm/page_alloc: ignore the exact initial compaction result
      mm/page_alloc: refactor the initial compaction handling
      mm/page_alloc: simplify __alloc_pages_slowpath() flow

 include/linux/gfp.h |   8 ++-
 mm/page_alloc.c     | 163 +++++++++++++++++++++++-----------------------------
 2 files changed, 78 insertions(+), 93 deletions(-)
---
base-commit: 186f32b9f92ad7ef6bb90d1d0e9692665cfbb69b
change-id: 20251216-thp-thisnode-tweak-c9c2acb3a627

Best regards,
-- 
Vlastimil Babka <vbabka@...e.cz>