From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 25E203B4E88 for ; Wed, 16 Sep 2026 01:35:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789522534; cv=none; b=Cr5Xe4piWNKOfswWHs4MOpEbMTI+8tPUBDapPPs079Wvn7I0s8JZY6ae3qcsJ7xlDIsIXyG09aI05XxXgIq/NMenMEGOkNJ9NFXk+jAuDV90LFujDnsRGJ55QyVms9e16Lk422aaStDv9Zs7FHrd/UgnDCHqssXi/RNhybzlvGs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789522534; c=relaxed/simple; bh=GkJvz2WNjxGQSHEza9ey9ho3ZnzM833hpCZoRbU6+IM=; h=Date:To:From:Subject:Message-Id; b=q8Swhk2oug+kXIUmypSMj4tI+4kfA3AEILpUfYaBgG9CNnb2+4poFpBUl7pHg0QXTH1NXNBu/zh00phC+Oq7K3bjnGj4EJn1ale1MqYeOcdiupuPC9dq4E2fGSvqhnlZ5uoApT2+sVZmxxecK+pIZAeAhF4eF3Vx0tTnkD/mHvw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=EFufIFMj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="EFufIFMj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7B8F1F000FF; Wed, 16 Sep 2026 01:35:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789522524; bh=qOgSScAhR4lq9nfJwbSQ9mrVq4kYHLW9pcjCDqxlyXI=; h=Date:To:From:Subject; b=EFufIFMjUU7RAixSw4GpJ2h5GLF5hGhUFnfoh04Pbd1jCs8w7WMm1R+mPZjuH5MW+ 3PVrK63sNpc3pv3LKU4F5YRYHOG++lKRj5/P9fHYzdCkFgH8tyXADWSPA/qw1o3zaB 6qvLSTJb1H9diRZKsn0RwLzyplrxCfNDGk6PECDk= Date: Tue, 15 Sep 2026 18:35:24 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,vbabka@kernel.org,surenb@google.com,mhocko@suse.com,hannes@cmpxchg.org,brendan.jackman@linux.dev,liuqiqi@kylinos.cn,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-page_alloc-apply-per-task-gfp-context-in-bulk-allocator.patch added to mm-new branch Message-Id: <20260916013524.C7B8F1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/page_alloc: apply per-task GFP context in bulk allocator has been added to the -mm mm-new branch. Its filename is mm-page_alloc-apply-per-task-gfp-context-in-bulk-allocator.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-apply-per-task-gfp-context-in-bulk-allocator.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Qiqi Liu Subject: mm/page_alloc: apply per-task GFP context in bulk allocator Date: Tue, 15 Sep 2026 15:49:28 +0800 alloc_pages_bulk_noprof() does not call current_gfp_context(), so per-task scoped allocation constraints (PF_MEMALLOC_NOIO, PF_MEMALLOC_NOFS, PF_MEMALLOC_PIN) are not applied on the bulk fast path. By ignoring PF_MEMALLOC_NOIO and PF_MEMALLOC_NOFS, the allocation can theoretically result in a deadlock. Ignoring PF_MEMALLOC_PIN also has consequences: without clearing __GFP_MOVABLE, prepare_alloc_pages() selects MIGRATE_MOVABLE for the PCP list, and a task with PF_MEMALLOC_PIN set receives movable pages from the bulk allocator. Once pinned, these pages can no longer be migrated but remain in MOVABLE pageblocks, violating the mobility contract. This can increase fragmentation and interfere with compaction or contiguous-memory allocations, eventually surfacing as higher allocation latency or allocation failures under memory pressure. Found via review of the bulk allocation tracepoint hooks [1]. Link: https://sashiko.dev/#/patchset/20260907120949.418450-1-liuqiqi%40kylinos.cn Link: https://lore.kernel.org/all/20260907120949.418450-1-liuqiqi@kylinos.cn/ [1] Link: https://lore.kernel.org/20260915074928.327471-1-liuqiqi@kylinos.cn Fixes: 387ba26fb1cb ("mm/page_alloc: add a bulk page allocator") Signed-off-by: Qiqi Liu Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka (SUSE) Cc: Brendan Jackman Cc: Johannes Weiner Cc: Michal Hocko Cc: Suren Baghdasaryan Cc: Zi Yan --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/page_alloc.c~mm-page_alloc-apply-per-task-gfp-context-in-bulk-allocator +++ a/mm/page_alloc.c @@ -5201,6 +5201,7 @@ unsigned long alloc_pages_bulk_noprof(gf /* May set ALLOC_NOFRAGMENT, fragmentation will return 1 page. */ gfp &= gfp_allowed_mask; + gfp = current_gfp_context(gfp); if (!prepare_alloc_pages(gfp, 0, preferred_nid, nodemask, &ac, &gfp, &alloc_flags)) goto out; _ Patches currently in -mm which might be from liuqiqi@kylinos.cn are mm-page_alloc-add-missing-hooks-to-bulk-allocation-path.patch mm-page_alloc-apply-per-task-gfp-context-in-bulk-allocator.patch