From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 625C44052AF for ; Mon, 3 Aug 2026 13:38:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785764285; cv=none; b=JMQCPR6prQhkvSBtJ6eyuB8tpIOVJRLf4bZwurbvFWq4Z3a5P+qHmPQskVmZZji0ZBxMKSnGT7fFEtpGMTPSMbT82NqMsoiguFXnReqH+eh5nFoDazN3fOLf9nhwzvXKeiDkKq+6mZYr3ghVLVE6YCvSkkHGWTMjvH83Stp7Wgo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785764285; c=relaxed/simple; bh=qAOL5IDICIJegnaGClpi5ht+KVdNjbuTSDgoo+LyWwE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IlaoJcbaXRoOqBxtoCZxxZsyZWn1OJQHu2hQLmd3XCRaGeMyLXvb3YIXD16H01S0L+CNEcWHYiplbQKrVNJ2PT59073cxj2s5hLY4wmYn2CdhHaal/QjdUUDbDDo8rEoAuZY0x/eL9/uCESMXD6da193HW/s3hyXUHktF2luKXQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NlDuf1Od; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NlDuf1Od" Received: by smtp.kernel.org (Postfix) with ESMTPS id 1D91EC2BCF7; Mon, 3 Aug 2026 13:38:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1785764285; bh=qAOL5IDICIJegnaGClpi5ht+KVdNjbuTSDgoo+LyWwE=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=NlDuf1OdSjHnkctrwJMJGolNde74KbAIULiheOzKk1wNv06s4TiCxLzCTL/C4c4/w FbJ/BOm618t6Y4g/uu+sjw1iz79mmuYYDUPxQOxpM2bsKZMcirFae4Tiye+Bd3/P2x DzjNqxNTktm5OTPRLIWRRLYK6Qu2+dfCziaNxg2lPujrctne5pRhwMQ8sASVVeU3YK OJxau6c58o6wIgjSqQm2hpHNeIofVH6Bb72Eg3fDFzm3aQrmKXEyxLXv2X2PVq4rP1 yBwSzxh901jWpbawai0t1ONFhW0WdLZNDkSq2siI+oyLv4pO+RaL9mPFdggCXk/98q ZCp5OCKv/jMGg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF68EC55182; Mon, 3 Aug 2026 13:38:04 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Mon, 03 Aug 2026 06:37:59 -0700 Subject: [PATCH v5 2/3] mm: hugetlb: Move mpol interpretation out of alloc_buddy_hugetlb_folio_with_mpol() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260803-hugetlb-mpol-interpretation-v5-2-af2b7089f8a9@google.com> References: <20260803-hugetlb-mpol-interpretation-v5-0-af2b7089f8a9@google.com> In-Reply-To: <20260803-hugetlb-mpol-interpretation-v5-0-af2b7089f8a9@google.com> To: Alistair Popple , Andrew Morton , Byungchul Park , David Hildenbrand , Gregory Price , Joshua Hahn , Matthew Brost , Muchun Song , Oscar Salvador , Rakie Kim , Ying Huang , Zi Yan , erdemaktas@google.com, fvdl@google.com, jiaqiyan@google.com, jthoughton@google.com, mhocko@kernel.org, michael.roth@amd.com, pasha.tatashin@soleen.com, pbonzini@redhat.com, peterx@redhat.com, pratyush@kernel.org, rick.p.edgecombe@intel.com, rientjes@google.com, roman.gushchin@linux.dev, seanjc@google.com, shakeel.butt@linux.dev, shivankg@amd.com, vannapurve@google.com, yan.y.zhao@intel.com, Jason Gunthorpe Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1785764284; l=4762; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=wYqvllJ825+3G1PTvuHSW07dYvdU6Lqe0qHUWN7iPXg=; b=hhdnZtqqlVB1rX6spiHuGLYVsQxCacg57E65NcWdbiU0wvPTL175Kov8PdD4TlSirrYO3htAn 4qQJuOqkg4XBEUhakN6nChqbcwfRaPZo0EJDSqR5FQQpBB20TepPmHo X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com From: Ackerley Tng Move memory policy interpretation out of alloc_buddy_hugetlb_folio_with_mpol() and into alloc_hugetlb_folio() to separate reading and interpretation of memory policy from actual allocation. This will later allow memory policy to be interpreted outside of the process of allocating a hugetlb folio entirely. This opens doors for other callers of the HugeTLB folio allocation function, such as guest_memfd, where memory may not always be mapped and hence may not have an associated vma. Introduce struct mempolicy_interpreted to hold all the components of an interpreted memory policy. Rename alloc_buddy_hugetlb_folio_with_mpol() to alloc_buddy_hugetlb_folio() since the function no longer interprets memory policy. No functional change intended. Reviewed-by: James Houghton Acked-by: Oscar Salvador Signed-off-by: Ackerley Tng --- include/uapi/linux/mempolicy.h | 2 +- mm/hugetlb.c | 54 ++++++++++++++++++++++++++++-------------- 2 files changed, 37 insertions(+), 19 deletions(-) diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 6c962d866e864..7f6fc9599693b 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -16,7 +16,7 @@ */ /* Policies */ -enum { +enum mempolicy_mode { MPOL_DEFAULT, MPOL_PREFERRED, MPOL_BIND, diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7985cfd21a03c..3a159de08a0b6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1317,6 +1317,12 @@ static unsigned long available_huge_pages(struct hstate *h) return h->free_huge_pages - h->resv_huge_pages; } +struct mempolicy_interpreted { + int nid; + nodemask_t *nodemask; + enum mempolicy_mode mode; +}; + static struct folio *dequeue_hugetlb_folio_vma(struct hstate *h, struct vm_area_struct *vma, unsigned long address) @@ -2138,32 +2144,28 @@ static struct folio *alloc_migrate_hugetlb_folio(struct hstate *h, gfp_t gfp_mas return folio; } -/* - * Use the VMA's mpolicy to allocate a huge page from the buddy. - */ static -struct folio *alloc_buddy_hugetlb_folio_with_mpol(struct hstate *h, - struct vm_area_struct *vma, unsigned long addr) +struct folio *alloc_buddy_hugetlb_folio(struct hstate *h, + gfp_t gfp_mask, struct mempolicy_interpreted *mpoli) { struct folio *folio = NULL; - struct mempolicy *mpol; - gfp_t gfp_mask = htlb_alloc_mask(h); - int nid; - nodemask_t *nodemask; + nodemask_t *nodemask = mpoli->nodemask; - nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask); - if (mpol_is_preferred_many(mpol)) { + if (mpoli->mode == MPOL_PREFERRED_MANY) { gfp_t gfp = gfp_mask & ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL); - folio = alloc_surplus_hugetlb_folio(h, gfp, nid, nodemask); + folio = alloc_surplus_hugetlb_folio(h, gfp, mpoli->nid, + nodemask); /* Fallback to all nodes if page==NULL */ nodemask = NULL; } - if (!folio) - folio = alloc_surplus_hugetlb_folio(h, gfp_mask, nid, nodemask); - mpol_cond_put(mpol); + if (!folio) { + folio = alloc_surplus_hugetlb_folio(h, gfp_mask, mpoli->nid, + nodemask); + } + return folio; } @@ -2853,7 +2855,7 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, int ret, idx; struct hugetlb_cgroup *h_cg = NULL; struct hugetlb_cgroup *h_cg_rsvd = NULL; - gfp_t gfp = htlb_alloc_mask(h) | __GFP_RETRY_MAYFAIL; + gfp_t gfp = htlb_alloc_mask(h); idx = hstate_index(h); @@ -2926,8 +2928,24 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, folio = dequeue_hugetlb_folio_vma(h, vma, addr); if (!folio) { + struct mempolicy_interpreted mpoli; + struct mempolicy *mpol; + nodemask_t *nodemask; + int nid; + spin_unlock_irq(&hugetlb_lock); - folio = alloc_buddy_hugetlb_folio_with_mpol(h, vma, addr); + nid = huge_node(vma, addr, gfp, &mpol, &nodemask); + mpoli = (struct mempolicy_interpreted){ + .nid = nid, +#ifdef CONFIG_NUMA + .mode = mpol ? mpol->mode : MPOL_DEFAULT, +#else + .mode = MPOL_DEFAULT, +#endif + .nodemask = nodemask, + }; + folio = alloc_buddy_hugetlb_folio(h, gfp, &mpoli); + mpol_cond_put(mpol); if (!folio) goto out_uncharge_cgroup; spin_lock_irq(&hugetlb_lock); @@ -2983,7 +3001,7 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma, } } - ret = mem_cgroup_charge_hugetlb(folio, gfp); + ret = mem_cgroup_charge_hugetlb(folio, gfp | __GFP_RETRY_MAYFAIL); /* * Unconditionally increment NR_HUGETLB here. If it turns out that * mem_cgroup_charge_hugetlb failed, then immediately free the page and -- 2.55.0.508.g3f0d502094-goog