[PATCH v3 00/16] mm: Some cleanups for page allocator APIs

[PATCH v3 00/16] mm: Some cleanups for page allocator APIs

[Brendan Jackman]

This is based on mm-new, it depends on moving alloc_tag to mm/ [0].

[0] https://lore.kernel.org/all/aj5QBtJcphPElczI@lucifer/

Some tweaks and cleanups for page allocator entrypoint and flags. This
is motivated by preparation for __GFP_UNMAPPED [1] (which will probably
become ALLOC_UNMAPPED in its next iteration), but all this is supposed
to be an improvement to the codebase in its own right: unifying code
paths, reducing API surface, and removing GFP flags.

[1] https://lore.kernel.org/all/20260320-page_alloc-unmapped-v2-0-28bf1bd54f41@google.com/

This started with unifying  __alloc_frozen_pages[_nolock]_noprof() and
expanded from there.

Unifying the nolock allocator entrypoint with the normal allocator
entrypoint means adding an alloc_flags argument to the later (only
exposed within mm/). This presents an opportunity to take advantage of
that arg to remove some GFP flags, if we add that alloc_flags arg a bit
more broadly to allocator entrypoints.

To distinguish between mm-internal and "public" allocator entrypoints,
it makes sense to use the __ prefix. There are already some public APIs
with that prefix. For *alloc_pages*, just removing those variants seems
like a nice cleanup anyway, so do that. For get_free_pages, the "__"
variant is the _only_ variant and it's very widely used, so it doesn't
seem worthwhile to modify that. Therefore, scope this "__" change
specifically to the *alloc_pages* API, which means we leave the
*folio_alloc* API untouched too, even though that could probably be
cleaned up if so desired.

Tested:

- KVM, mm, and BPF selftests in a QEMU VM

- kunit.py on x86_64

- For the ALLOC_NO_CODETAG bits I just booted a VM and read
  /proc/allocinfo. I confirmed that if I remove ALLOC_NO_CODETAG, the
  kernel crashes in early boot, so I was at least booting code that
  depends on this logic.

I used Google's internal version of Antigravity (AI coding harness) to
do the repetitive bits, those commits are marked with Assisted-by, the
rest is manual.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
Changes in v3:
- Created mm/page_alloc.h
- Fixed EXPORT_SYMBOL() issues
- Reworded commit messages per Sashiko's pointers
- Dropped rename of alloc_flags arg in prepare_alloc_pages() (Suren)
- Renamed gfp_to_alloc_flags_nonblocking() too after rebasing onto:
  https://lore.kernel.org/all/20260623004600.113347-1-jp.kobryn@linux.dev/
- Link to v2: https://patch.msgid.link/20260622-alloc-trylock-v2-0-31f31367d420@google.com

Changes in v2:
- Fixed up whitespace in nolock unification patch
- Introduced ALLOC_DEFAULT to replace literal 0 for alloc_flags
- All other patches are new
- Link to v1: https://patch.msgid.link/20260617-alloc-trylock-v1-1-83fd7858832e@google.com

---
Brendan Jackman (16):
      mm/page_alloc: rename ALLOC_TRYLOCK -> ALLOC_NOLOCK
      mm/page_alloc: some renames to clarify alloc_flags scopes
      mm: name some args in a function declaration
      mm: Split out internal page_alloc.h
      mm/page_alloc: unify __alloc_frozen_pages[_nolock]_noprof()
      mm/page_alloc: relax GFP WARN in nolock allocs
      mm: move some stuff to mm/page_alloc.h
      perf/x86/intel: Use higher-level allocator API
      KVM: VMX: Use higher-level allocator API
      x86/virt: Use higher-level allocator API
      sgi-xp: Use higher-level allocator API
      net/funeth: Switch to higher-level allocator API
      mm: Remove __alloc_pages_node()
      mm: Move __alloc_pages() to mm/page_alloc.h
      mm: replace __GFP_NO_CODETAG with ALLOC_NO_CODETAG
      mm: remove the __GFP_NO_OBJ_EXT flag

 Documentation/admin-guide/cgroup-v1/cpusets.rst  |   2 +-
 Documentation/admin-guide/mm/transhuge.rst       |   2 +-
 MAINTAINERS                                      |   1 +
 arch/x86/events/intel/ds.c                       |   6 +-
 arch/x86/kvm/vmx/vmx.c                           |   2 +-
 arch/x86/virt/hw.c                               |   2 +-
 drivers/misc/sgi-xp/xpc_uv.c                     |   2 +-
 drivers/net/ethernet/fungible/funeth/funeth_rx.c |   2 +-
 include/linux/gfp.h                              |  54 +---
 mm/alloc_tag.c                                   |  22 +-
 mm/compaction.c                                  |   5 +-
 mm/hugetlb.c                                     |   4 +-
 mm/internal.h                                    | 253 ------------------
 mm/khugepaged.c                                  |   1 +
 mm/memory-failure.c                              |   1 +
 mm/memory_hotplug.c                              |   1 +
 mm/mempolicy.c                                   |  11 +-
 mm/mm_init.c                                     |   1 +
 mm/page_alloc.c                                  | 259 ++++++++++---------
 mm/page_alloc.h                                  | 316 +++++++++++++++++++++++
 mm/page_frag_cache.c                             |   6 +-
 mm/page_isolation.c                              |   1 +
 mm/page_owner.c                                  |   2 +-
 mm/show_mem.c                                    |   1 +
 mm/slub.c                                        |   7 +-
 mm/swap.c                                        |   1 +
 mm/vmscan.c                                      |   1 +
 mm/vmstat.c                                      |   1 +
 tools/include/linux/gfp_types.h                  |   7 -
 29 files changed, 506 insertions(+), 468 deletions(-)
---
base-commit: ec005628e9dbcef26b761fa860f264fe6e5fd690
change-id: 20260617-alloc-trylock-14ad37dab337

Best regards,
--  
Brendan Jackman <jackmanb@google.com>

[PATCH v3 09/16] KVM: VMX: Use higher-level allocator API

[Brendan Jackman]

The difference between __alloc_pages_node() and alloc_pages_node() is
that the latter allows you to pass NUMA_NO_NODE.

The former is going away and the latter works fine here so switch over.

No functional change intended.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Assisted-by: Gemini:unknown-version
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
 arch/x86/kvm/vmx/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2325be57d3d75..ad6a7fc6a54da 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3028,7 +3028,7 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
 	struct page *pages;
 	struct vmcs *vmcs;
 
-	pages = __alloc_pages_node(node, flags, 0);
+	pages = alloc_pages_node(node, flags, 0);
 	if (!pages)
 		return NULL;
 	vmcs = page_address(pages);

-- 
2.54.0

Re: [PATCH v3 00/16] mm: Some cleanups for page allocator APIs

[Mike Rapoport]

Hi Brendan,

On Mon, Jun 29, 2026 at 01:11:49PM +0000, Brendan Jackman wrote:
> 
> Some tweaks and cleanups for page allocator entrypoint and flags. This
> is motivated by preparation for __GFP_UNMAPPED [1] (which will probably
> become ALLOC_UNMAPPED in its next iteration), but all this is supposed
> to be an improvement to the codebase in its own right: unifying code
> paths, reducing API surface, and removing GFP flags.
> 
> Tested:
> 
> - KVM, mm, and BPF selftests in a QEMU VM
> 
> - kunit.py on x86_64
> 
> - For the ALLOC_NO_CODETAG bits I just booted a VM and read
>   /proc/allocinfo. I confirmed that if I remove ALLOC_NO_CODETAG, the
>   kernel crashes in early boot, so I was at least booting code that
>   depends on this logic.

Heads up before the full kbuild report:

CI has tested the following submission:
Status:     FAILURE
Name:       [v3,00/16] mm: Some cleanups for page allocator APIs
Patchwork:  https://patchwork.kernel.org/project/linux-mm/list/?series=1118244&state=*
Matrix:     https://github.com/linux-mm/linux-mm/actions/runs/28375636866

> I used Google's internal version of Antigravity (AI coding harness) to
> do the repetitive bits, those commits are marked with Assisted-by, the
> rest is manual.
> 
> Signed-off-by: Brendan Jackman <jackmanb@google.com>
> ---

-- 
Sincerely yours,
Mike.

Re: [PATCH v3 00/16] mm: Some cleanups for page allocator APIs

[Brendan Jackman]

On Mon, 29 Jun 2026 at 16:00, Mike Rapoport <rppt@kernel.org> wrote:
>
> Hi Brendan,
>
> On Mon, Jun 29, 2026 at 01:11:49PM +0000, Brendan Jackman wrote:
> >
> > Some tweaks and cleanups for page allocator entrypoint and flags. This
> > is motivated by preparation for __GFP_UNMAPPED [1] (which will probably
> > become ALLOC_UNMAPPED in its next iteration), but all this is supposed
> > to be an improvement to the codebase in its own right: unifying code
> > paths, reducing API surface, and removing GFP flags.
> >
> > Tested:
> >
> > - KVM, mm, and BPF selftests in a QEMU VM
> >
> > - kunit.py on x86_64
> >
> > - For the ALLOC_NO_CODETAG bits I just booted a VM and read
> >   /proc/allocinfo. I confirmed that if I remove ALLOC_NO_CODETAG, the
> >   kernel crashes in early boot, so I was at least booting code that
> >   depends on this logic.
>
> Heads up before the full kbuild report:
>
> CI has tested the following submission:
> Status:     FAILURE
> Name:       [v3,00/16] mm: Some cleanups for page allocator APIs
> Patchwork:  https://patchwork.kernel.org/project/linux-mm/list/?series=1118244&state=*
> Matrix:     https://github.com/linux-mm/linux-mm/actions/runs/28375636866

Agh, thanks, I broke the build for CMA.

I thought I had this covered in my local test scripts. I will fix that
first then I'll send a fixup for the patch.

Re: [PATCH v3 00/16] mm: Some cleanups for page allocator APIs

[Brendan Jackman]

On Mon, 29 Jun 2026 at 16:30, Brendan Jackman <jackmanb@google.com> wrote:
>
> On Mon, 29 Jun 2026 at 16:00, Mike Rapoport <rppt@kernel.org> wrote:
> >
> > Hi Brendan,
> >
> > On Mon, Jun 29, 2026 at 01:11:49PM +0000, Brendan Jackman wrote:
> > >
> > > Some tweaks and cleanups for page allocator entrypoint and flags. This
> > > is motivated by preparation for __GFP_UNMAPPED [1] (which will probably
> > > become ALLOC_UNMAPPED in its next iteration), but all this is supposed
> > > to be an improvement to the codebase in its own right: unifying code
> > > paths, reducing API surface, and removing GFP flags.
> > >
> > > Tested:
> > >
> > > - KVM, mm, and BPF selftests in a QEMU VM
> > >
> > > - kunit.py on x86_64
> > >
> > > - For the ALLOC_NO_CODETAG bits I just booted a VM and read
> > >   /proc/allocinfo. I confirmed that if I remove ALLOC_NO_CODETAG, the
> > >   kernel crashes in early boot, so I was at least booting code that
> > >   depends on this logic.
> >
> > Heads up before the full kbuild report:
> >
> > CI has tested the following submission:
> > Status:     FAILURE
> > Name:       [v3,00/16] mm: Some cleanups for page allocator APIs
> > Patchwork:  https://patchwork.kernel.org/project/linux-mm/list/?series=1118244&state=*
> > Matrix:     https://github.com/linux-mm/linux-mm/actions/runs/28375636866
>
> Agh, thanks, I broke the build for CMA.
>
> I thought I had this covered in my local test scripts. I will fix that
> first then I'll send a fixup for the patch.

OK my scripts are indeed checking CMA, the issue is that I didn't
build with NUMA_BALANCING.

I guess Suren was right[0] and I really should build allmodconfig (at
least vmlinux) before sending patches. I was a bit skeptical that this
was an especially useful config to build, but now I realise it just
maximises coverage, even if it does so under a pretty arbitrary
configuration.

[0] https://lore.kernel.org/all/CAJuCfpHAMaK2sZYSgS750CvgksCKEfOmLzZasXdBup+CrS-3Pg@mail.gmail.com/

Here are the fixes:

diff --git i/mm/migrate.c w/mm/migrate.c
index d9b23909d716c..8e0a6fb3f6618 100644
--- i/mm/migrate.c
+++ w/mm/migrate.c
@@ -49,6 +49,7 @@
 #include <trace/events/migrate.h>

 #include "internal.h"
+#include "page_alloc.h"
 #include "swap.h"

 static const struct movable_operations *offline_movable_ops;
diff --git i/mm/page_reporting.c w/mm/page_reporting.c
index 7418f2e500bb4..c7325704c3202 100644
--- i/mm/page_reporting.c
+++ w/mm/page_reporting.c
@@ -8,6 +8,7 @@
 #include <linux/delay.h>
 #include <linux/scatterlist.h>

+#include "page_alloc.h"
 #include "page_reporting.h"
 #include "internal.h"

diff --git i/mm/shuffle.c w/mm/shuffle.c
index fb1393b8b3a9d..82a2c7725a08a 100644
--- i/mm/shuffle.c
+++ w/mm/shuffle.c
@@ -7,6 +7,7 @@
 #include <linux/random.h>
 #include <linux/moduleparam.h>
 #include "internal.h"
+#include "page_alloc.h"
 #include "shuffle.h"

 DEFINE_STATIC_KEY_FALSE(page_alloc_shuffle_key);

RE: -EXT-[PATCH v3 09/16] KVM: VMX: Use higher-level allocator API

[Soderlund, David]

Can someone please remove me from this list.  I've requested a couple of times.

  Thanks,
     David

-----Original Message-----
From: Brendan Jackman <jackmanb@google.com> 
Sent: Monday, June 29, 2026 7:12 AM
To: Andrew Morton <akpm@linux-foundation.org>; Vlastimil Babka <vbabka@kernel.org>; Suren Baghdasaryan <surenb@google.com>; Michal Hocko <mhocko@suse.com>; Johannes Weiner <hannes@cmpxchg.org>; Zi Yan <ziy@nvidia.com>; Muchun Song <muchun.song@linux.dev>; Oscar Salvador <osalvador@suse.de>; David Hildenbrand <david@kernel.org>; Lorenzo Stoakes <ljs@kernel.org>; Liam R. Howlett <liam@infradead.org>; Mike Rapoport <rppt@kernel.org>; Matthew Brost <matthew.brost@intel.com>; Joshua Hahn <joshua.hahnjy@gmail.com>; Rakie Kim <rakie.kim@sk.com>; Byungchul Park <byungchul@sk.com>; Ying Huang <ying.huang@linux.alibaba.com>; Alistair Popple <apopple@nvidia.com>; Hao Li <hao.li@linux.dev>; Christoph Lameter <cl@gentwo.org>; David Rientjes <rientjes@google.com>; Roman Gushchin <roman.gushchin@linux.dev>; Sebastian Andrzej Siewior <bigeasy@linutronix.de>; Clark Williams <clrkwllms@kernel.org>; Steven Rostedt <rostedt@goodmis.org>
Cc: Harry Yoo (Oracle) <harry@kernel.org>; Gregory Price <gourry@gourry.net>; Johannes Weiner <hannes@cmpxchg.org>; Alexei Starovoitov <ast@kernel.org>; Matthew Wilcox <willy@infradead.org>; Hao Ge <hao.ge@linux.dev>; linux-mm@kvack.org; linux-kernel@vger.kernel.org; linux-rt-devel@lists.linux.dev; Brendan Jackman <jackmanb@google.com>; Sean Christopherson <seanjc@google.com>; Paolo Bonzini <pbonzini@redhat.com>; kvm@vger.kernel.org
Subject: -EXT-[PATCH v3 09/16] KVM: VMX: Use higher-level allocator API

WARNING:  This message is from an external source.  Evaluate the message carefully BEFORE clicking on links or opening attachments.

The difference between __alloc_pages_node() and alloc_pages_node() is that the latter allows you to pass NUMA_NO_NODE.

The former is going away and the latter works fine here so switch over.

No functional change intended.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Assisted-by: Gemini:unknown-version
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
 arch/x86/kvm/vmx/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 2325be57d3d75..ad6a7fc6a54da 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3028,7 +3028,7 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
        struct page *pages;
        struct vmcs *vmcs;

-       pages = __alloc_pages_node(node, flags, 0);
+       pages = alloc_pages_node(node, flags, 0);
        if (!pages)
                return NULL;
        vmcs = page_address(pages);

--
2.54.0