From: Lorenzo Stoakes <ljs@kernel•org>
To: "Michael S. Tsirkin" <mst@redhat•com>
Cc: linux-kernel@vger•kernel.org,
"David Hildenbrand (Arm)" <david@kernel•org>,
"Jason Wang" <jasowang@redhat•com>,
"Xuan Zhuo" <xuanzhuo@linux•alibaba.com>,
"Eugenio Pérez" <eperezma@redhat•com>,
"Muchun Song" <muchun.song@linux•dev>,
"Oscar Salvador" <osalvador@suse•de>,
"Andrew Morton" <akpm@linux-foundation•org>,
"Liam R. Howlett" <liam@infradead•org>,
"Vlastimil Babka" <vbabka@kernel•org>,
"Mike Rapoport" <rppt@kernel•org>,
"Suren Baghdasaryan" <surenb@google•com>,
"Michal Hocko" <mhocko@suse•com>,
"Brendan Jackman" <jackmanb@google•com>,
"Johannes Weiner" <hannes@cmpxchg•org>, "Zi Yan" <ziy@nvidia•com>,
"Baolin Wang" <baolin.wang@linux•alibaba.com>,
"Nico Pache" <npache@redhat•com>,
"Ryan Roberts" <ryan.roberts@arm•com>,
"Dev Jain" <dev.jain@arm•com>, "Barry Song" <baohua@kernel•org>,
"Lance Yang" <lance.yang@linux•dev>,
"Hugh Dickins" <hughd@google•com>,
"Matthew Brost" <matthew.brost@intel•com>,
"Joshua Hahn" <joshua.hahnjy@gmail•com>,
"Rakie Kim" <rakie.kim@sk•com>,
"Byungchul Park" <byungchul@sk•com>,
"Gregory Price" <gourry@gourry•net>,
"Ying Huang" <ying.huang@linux•alibaba.com>,
"Alistair Popple" <apopple@nvidia•com>,
"Christoph Lameter" <cl@gentwo•org>,
"David Rientjes" <rientjes@google•com>,
"Roman Gushchin" <roman.gushchin@linux•dev>,
"Harry Yoo" <harry.yoo@oracle•com>,
"Axel Rasmussen" <axelrasmussen@google•com>,
"Yuanchu Xie" <yuanchu@google•com>, "Wei Xu" <weixugc@google•com>,
"Chris Li" <chrisl@kernel•org>,
"Kairui Song" <kasong@tencent•com>,
"Kemeng Shi" <shikemeng@huaweicloud•com>,
"Nhat Pham" <nphamcs@gmail•com>, "Baoquan He" <bhe@redhat•com>,
virtualization@lists•linux.dev, linux-mm@kvack•org,
"Andrea Arcangeli" <aarcange@redhat•com>
Subject: Re: [PATCH v10 06/37] mm: move vma_alloc_folio_noprof to page_alloc.c
Date: Mon, 8 Jun 2026 11:05:09 +0100 [thread overview]
Message-ID: <aiaSI4SlVDIa4Y73@lucifer> (raw)
In-Reply-To: <5a3034dc7b3d5ea1edcc8b9baff63c980b7ae434.1780906288.git.mst@redhat.com>
On Mon, Jun 08, 2026 at 04:35:05AM -0400, Michael S. Tsirkin wrote:
> Move vma_alloc_folio_noprof() from an inline in gfp.h (for !NUMA)
> and mempolicy.c (for NUMA) to page_alloc.c.
This is an incorrectly described patch. You're not moving the function,
you're also altering its behaviour.
Do the two changes separately, and justify why you are changing this
behaviour.
>
> This prepares for a subsequent patch that will thread user_addr
> through the allocator: having vma_alloc_folio_noprof in page_alloc.c
> means user_addr can be passed to the internal allocation path
> without changing public API signatures or duplicating plumbing
> in both gfp.h and mempolicy.c.
We seem to have a fun mess with some NUMA stuff living in mempolicy.c and
some living in page_alloc.c with #ifdef CONFIG_NUMA's around it.
But I guess that was a pre-existing problem...
>
> The !NUMA path gains the VM_DROPPABLE -> __GFP_NOWARN check
> that the NUMA path already had.
What is your justification for doing this? Commit messages that put the
code changes in English are not helpful, tell me _why_ you are doing this.
It seems that you're suggesting not doing this was a pre-existing bug?
Therefore it would need a fixes/cc: stable no? Unless you feel this isn't
significant enough to require that?
If not, then why are you changing this behaviour?
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat•com>
> Assisted-by: Claude:claude-opus-4-6
> Assisted-by: cursor-agent:GPT-5.4-xhigh
> ---
> include/linux/gfp.h | 9 ++-------
> mm/mempolicy.c | 32 --------------------------------
> mm/page_alloc.c | 43 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 45 insertions(+), 39 deletions(-)
>
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index 51ef13ed756e..7ccbda35b9ad 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -318,13 +318,13 @@ static inline struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask,
>
> #define alloc_pages_node(...) alloc_hooks(alloc_pages_node_noprof(__VA_ARGS__))
>
> +struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order,
> + struct vm_area_struct *vma, unsigned long addr);
> #ifdef CONFIG_NUMA
> struct page *alloc_pages_noprof(gfp_t gfp, unsigned int order);
> struct folio *folio_alloc_noprof(gfp_t gfp, unsigned int order);
> struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
> struct mempolicy *mpol, pgoff_t ilx, int nid);
> -struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order, struct vm_area_struct *vma,
> - unsigned long addr);
> #else
> static inline struct page *alloc_pages_noprof(gfp_t gfp_mask, unsigned int order)
> {
> @@ -339,11 +339,6 @@ static inline struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int orde
> {
> return folio_alloc_noprof(gfp, order);
> }
> -static inline struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order,
> - struct vm_area_struct *vma, unsigned long addr)
> -{
> - return folio_alloc_noprof(gfp, order);
> -}
> #endif
>
> #define alloc_pages(...) alloc_hooks(alloc_pages_noprof(__VA_ARGS__))
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index d139b074a599..a1707ad498a8 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -2516,38 +2516,6 @@ struct folio *folio_alloc_mpol_noprof(gfp_t gfp, unsigned int order,
> return page_rmappable_folio(page);
> }
>
> -/**
> - * vma_alloc_folio - Allocate a folio for a VMA.
> - * @gfp: GFP flags.
> - * @order: Order of the folio.
> - * @vma: Pointer to VMA.
> - * @addr: Virtual address of the allocation. Must be inside @vma.
> - *
> - * Allocate a folio for a specific address in @vma, using the appropriate
> - * NUMA policy. The caller must hold the mmap_lock of the mm_struct of the
> - * VMA to prevent it from going away. Should be used for all allocations
> - * for folios that will be mapped into user space, excepting hugetlbfs, and
> - * excepting where direct use of folio_alloc_mpol() is more appropriate.
> - *
> - * Return: The folio on success or NULL if allocation fails.
> - */
> -struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order, struct vm_area_struct *vma,
> - unsigned long addr)
> -{
> - struct mempolicy *pol;
> - pgoff_t ilx;
> - struct folio *folio;
> -
> - if (vma->vm_flags & VM_DROPPABLE)
> - gfp |= __GFP_NOWARN;
> -
> - pol = get_vma_policy(vma, addr, order, &ilx);
> - folio = folio_alloc_mpol_noprof(gfp, order, pol, ilx, numa_node_id());
> - mpol_cond_put(pol);
> - return folio;
> -}
> -EXPORT_SYMBOL(vma_alloc_folio_noprof);
> -
> struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned order)
> {
> struct mempolicy *pol = &default_policy;
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 8dae5b3f5876..6a605d05e8cd 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -5286,6 +5286,49 @@ struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_
> }
> EXPORT_SYMBOL(__folio_alloc_noprof);
>
> +#ifdef CONFIG_NUMA
> +/**
> + * vma_alloc_folio - Allocate a folio for a VMA.
> + * @gfp: GFP flags.
> + * @order: Order of the folio.
> + * @vma: Pointer to VMA.
> + * @addr: Virtual address of the allocation. Must be inside @vma.
> + *
> + * Allocate a folio for a specific address in @vma, using the appropriate
> + * NUMA policy. The caller must hold the mmap_lock of the mm_struct of the
> + * VMA to prevent it from going away. Should be used for all allocations
> + * for folios that will be mapped into user space, excepting hugetlbfs, and
> + * excepting where direct use of folio_alloc_mpol() is more appropriate.
> + *
> + * Return: The folio on success or NULL if allocation fails.
> + */
> +struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order,
> + struct vm_area_struct *vma, unsigned long addr)
> +{
> + struct mempolicy *pol;
> + pgoff_t ilx;
> + struct folio *folio;
> +
> + if (vma->vm_flags & VM_DROPPABLE)
> + gfp |= __GFP_NOWARN;
> +
> + pol = get_vma_policy(vma, addr, order, &ilx);
> + folio = folio_alloc_mpol_noprof(gfp, order, pol, ilx, numa_node_id());
> + mpol_cond_put(pol);
> + return folio;
> +}
> +#else
> +struct folio *vma_alloc_folio_noprof(gfp_t gfp, int order,
> + struct vm_area_struct *vma, unsigned long addr)
> +{
> + if (vma->vm_flags & VM_DROPPABLE)
> + gfp |= __GFP_NOWARN;
> +
> + return folio_alloc_noprof(gfp, order);
> +}
> +#endif
> +EXPORT_SYMBOL(vma_alloc_folio_noprof);
> +
> /*
> * Common helper functions. Never use with __GFP_HIGHMEM because the returned
> * address cannot represent highmem pages. Use alloc_pages and then kmap if
> --
> MST
>
Thanks, Lorenzo
next prev parent reply other threads:[~2026-06-08 10:05 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-08 8:33 [PATCH v10 00/37] mm/virtio: skip redundant zeroing of host-zeroed pages Michael S. Tsirkin
2026-06-08 8:34 ` [PATCH v10 01/37] mm: mempolicy: fix interleave index calculation Michael S. Tsirkin
2026-06-08 9:43 ` Lorenzo Stoakes
2026-06-08 8:34 ` [PATCH v10 02/37] mm: memory-failure: serialize TestSetPageHWPoison with zone->lock Michael S. Tsirkin
2026-06-08 9:43 ` Lorenzo Stoakes
2026-06-08 13:48 ` Michael S. Tsirkin
2026-06-08 14:14 ` Lorenzo Stoakes
2026-06-08 16:20 ` Andrew Morton
2026-06-08 8:34 ` [PATCH v10 03/37] mm: page_alloc: propagate PageReported flag across buddy splits Michael S. Tsirkin
2026-06-08 9:52 ` Lorenzo Stoakes
2026-06-08 12:50 ` Matthew Wilcox
2026-06-08 8:34 ` [PATCH v10 04/37] mm: page_reporting: allow driver to set batch capacity Michael S. Tsirkin
2026-06-08 8:34 ` [PATCH v10 05/37] mm: hugetlb: remove dead alloc_hugetlb_folio stub Michael S. Tsirkin
2026-06-08 9:56 ` Lorenzo Stoakes
2026-06-08 8:35 ` [PATCH v10 06/37] mm: move vma_alloc_folio_noprof to page_alloc.c Michael S. Tsirkin
2026-06-08 10:05 ` Lorenzo Stoakes [this message]
2026-06-08 8:35 ` [PATCH v10 07/37] mm: thread user_addr through page allocator for cache-friendly zeroing Michael S. Tsirkin
2026-06-08 10:23 ` Lorenzo Stoakes
2026-06-08 11:06 ` Lorenzo Stoakes
2026-06-08 13:04 ` Matthew Wilcox
2026-06-08 13:09 ` Lorenzo Stoakes
2026-06-08 14:26 ` David Hildenbrand (Arm)
2026-06-08 14:31 ` Matthew Wilcox
2026-06-08 14:37 ` David Hildenbrand (Arm)
2026-06-08 14:44 ` Matthew Wilcox
2026-06-08 14:55 ` David Hildenbrand (Arm)
2026-06-08 11:08 ` David Hildenbrand (Arm)
2026-06-08 15:27 ` Zi Yan
2026-06-08 8:35 ` [PATCH v10 08/37] mm: add alloc_contig_frozen_pages_user " Michael S. Tsirkin
2026-06-08 10:29 ` Lorenzo Stoakes
2026-06-08 8:35 ` [PATCH v10 09/37] mm: hugetlb: thread user_addr through gigantic page allocation Michael S. Tsirkin
2026-06-08 8:36 ` [PATCH v10 10/37] mm: add folio_zero_user stub for configs without THP/HUGETLBFS Michael S. Tsirkin
2026-06-08 9:12 ` Lorenzo Stoakes
2026-06-08 8:36 ` [PATCH v10 11/37] mm: page_alloc: move prep_compound_page before post_alloc_hook Michael S. Tsirkin
2026-06-08 10:33 ` Lorenzo Stoakes
2026-06-08 8:36 ` [PATCH v10 12/37] mm: use folio_zero_user for user pages in post_alloc_hook Michael S. Tsirkin
2026-06-08 11:23 ` Lorenzo Stoakes
2026-06-08 15:53 ` Gregory Price
2026-06-08 8:36 ` [PATCH v10 13/37] mm: use __GFP_ZERO in vma_alloc_zeroed_movable_folio Michael S. Tsirkin
2026-06-08 10:39 ` Lorenzo Stoakes
2026-06-08 10:55 ` Lorenzo Stoakes
2026-06-08 8:37 ` [PATCH v10 14/37] mm: remove arch vma_alloc_zeroed_movable_folio overrides Michael S. Tsirkin
2026-06-08 11:29 ` Lorenzo Stoakes
2026-06-08 8:37 ` [PATCH v10 15/37] mm: alloc_anon_folio: pass raw fault address to vma_alloc_folio Michael S. Tsirkin
2026-06-08 11:35 ` Lorenzo Stoakes
2026-06-08 8:37 ` [PATCH v10 16/37] mm: alloc_swap_folio: " Michael S. Tsirkin
2026-06-08 11:37 ` Lorenzo Stoakes
2026-06-08 15:59 ` Gregory Price
2026-06-08 8:37 ` [PATCH v10 17/37] mm: page_reporting: skip redundant zeroing of host-zeroed reported pages Michael S. Tsirkin
2026-06-08 12:00 ` Lorenzo Stoakes
2026-06-08 16:09 ` Gregory Price
2026-06-08 8:38 ` [PATCH v10 18/37] mm: page_alloc: use aliasing checks instead of user_alloc_needs_zeroing Michael S. Tsirkin
2026-06-08 11:39 ` Lorenzo Stoakes
2026-06-08 8:38 ` [PATCH v10 19/37] mm: page_alloc: clear PG_zeroed on buddy merge if not both zero Michael S. Tsirkin
2026-06-08 11:47 ` Lorenzo Stoakes
2026-06-08 8:38 ` [PATCH v10 20/37] mm: page_alloc: preserve PG_zeroed in page_del_and_expand Michael S. Tsirkin
2026-06-08 8:38 ` [PATCH v10 21/37] mm: page_alloc: propagate PG_zeroed in split_large_buddy Michael S. Tsirkin
2026-06-08 8:38 ` [PATCH v10 22/37] mm: add free_frozen_pages_zeroed Michael S. Tsirkin
2026-06-08 12:06 ` Lorenzo Stoakes
2026-06-08 8:38 ` [PATCH v10 23/37] mm: page_alloc: skip kernel_init_pages for FPI_ZEROED when safe Michael S. Tsirkin
2026-06-08 12:18 ` Lorenzo Stoakes
2026-06-08 8:38 ` [PATCH v10 24/37] mm: add put_page_zeroed and folio_put_zeroed Michael S. Tsirkin
2026-06-08 12:25 ` Lorenzo Stoakes
2026-06-08 12:46 ` David Hildenbrand (Arm)
2026-06-08 14:08 ` Michael S. Tsirkin
2026-06-08 14:28 ` David Hildenbrand (Arm)
2026-06-08 8:39 ` [PATCH v10 25/37] mm: use __GFP_ZERO in alloc_anon_folio Michael S. Tsirkin
2026-06-08 12:29 ` Lorenzo Stoakes
2026-06-08 8:39 ` [PATCH v10 26/37] mm: vma_alloc_anon_folio_pmd: pass raw fault address to vma_alloc_folio Michael S. Tsirkin
2026-06-08 12:30 ` Lorenzo Stoakes
2026-06-08 8:39 ` [PATCH v10 27/37] mm: use __GFP_ZERO in vma_alloc_anon_folio_pmd Michael S. Tsirkin
2026-06-08 12:32 ` Lorenzo Stoakes
2026-06-08 8:39 ` [PATCH v10 28/37] mm: hugetlb: add gfp parameter and skip zeroing for zeroed pages Michael S. Tsirkin
2026-06-08 12:44 ` Lorenzo Stoakes
2026-06-08 8:39 ` [PATCH v10 29/37] mm: memfd: skip zeroing for zeroed hugetlb pool pages Michael S. Tsirkin
2026-06-08 12:47 ` Lorenzo Stoakes
2026-06-08 8:39 ` [PATCH v10 30/37] mm: page_reporting: add per-page zeroed bitmap for host feedback Michael S. Tsirkin
2026-06-08 8:39 ` [PATCH v10 31/37] virtio_balloon: submit reported pages as individual buffers Michael S. Tsirkin
2026-06-08 8:40 ` [PATCH v10 32/37] virtio_balloon: disable indirect descriptors Michael S. Tsirkin
2026-06-08 8:40 ` [PATCH v10 33/37] mm: page_reporting: add flush parameter with page budget Michael S. Tsirkin
2026-06-08 8:40 ` [PATCH v10 34/37] virtio_balloon: skip zeroing for host-zeroed reported pages Michael S. Tsirkin
2026-06-08 8:40 ` [PATCH v10 35/37] virtio_balloon: disable reporting zeroed optimization for confidential guests Michael S. Tsirkin
2026-06-08 8:40 ` [PATCH v10 36/37] mm: balloon: use put_page_zeroed for zeroed balloon pages Michael S. Tsirkin
2026-06-08 11:10 ` David Hildenbrand (Arm)
2026-06-08 8:40 ` [PATCH v10 37/37] virtio_balloon: implement VIRTIO_BALLOON_F_DEVICE_INIT_ON_INFLATE Michael S. Tsirkin
2026-06-08 9:17 ` [PATCH v10 00/37] mm/virtio: skip redundant zeroing of host-zeroed pages Lorenzo Stoakes
2026-06-08 12:52 ` Lorenzo Stoakes
2026-06-08 11:02 ` Vlastimil Babka (SUSE)
2026-06-08 11:13 ` Vlastimil Babka (SUSE)
2026-06-08 15:45 ` Gregory Price
2026-06-08 17:50 ` Lorenzo Stoakes
2026-06-08 14:21 ` Matthew Wilcox
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