* [PATCH V3 (RESEND) 2/3] mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf()
2020-06-18 1:15 [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory Anshuman Khandual
@ 2020-06-18 1:15 ` Anshuman Khandual
2020-07-02 14:07 ` Catalin Marinas
2020-06-18 8:56 ` [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory Mike Rapoport
2020-06-23 7:39 ` Jia He
2 siblings, 1 reply; 8+ messages in thread
From: Anshuman Khandual @ 2020-06-18 1:15 UTC (permalink / raw)
To: linux-mm
Cc: x86, H. Peter Anvin, Anshuman Khandual, Peter Zijlstra,
Catalin Marinas, Dave Hansen, linuxppc-dev, linux-kernel,
Ingo Molnar, Paul Mackerras, Andy Lutomirski, Borislav Petkov,
Thomas Gleixner, Will Deacon, Andrew Morton, linux-arm-kernel
There are many instances where vmemap allocation is often switched between
regular memory and device memory just based on whether altmap is available
or not. vmemmap_alloc_block_buf() is used in various platforms to allocate
vmemmap mappings. Lets also enable it to handle altmap based device memory
allocation along with existing regular memory allocations. This will help
in avoiding the altmap based allocation switch in many places.
While here also implement a regular memory allocation fallback mechanism
when the first preferred device memory allocation fails. This will ensure
preserving the existing semantics on powerpc platform. To summarize there
are three different methods to call vmemmap_alloc_block_buf().
(., NULL, false) /* Allocate from system RAM */
(., altmap, false) /* Allocate from altmap without any fallback */
(., altmap, true) /* Allocate from altmap with fallback (system RAM) */
Cc: Catalin Marinas <catalin.marinas@arm•com>
Cc: Will Deacon <will@kernel•org>
Cc: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: Paul Mackerras <paulus@samba•org>
Cc: Michael Ellerman <mpe@ellerman•id.au>
Cc: Dave Hansen <dave.hansen@linux•intel.com>
Cc: Andy Lutomirski <luto@kernel•org>
Cc: Peter Zijlstra <peterz@infradead•org>
Cc: Thomas Gleixner <tglx@linutronix•de>
Cc: Ingo Molnar <mingo@redhat•com>
Cc: Borislav Petkov <bp@alien8•de>
Cc: "H. Peter Anvin" <hpa@zytor•com>
Cc: Andrew Morton <akpm@linux-foundation•org>
Cc: x86@kernel•org
Cc: linux-arm-kernel@lists•infradead.org
Cc: linuxppc-dev@lists•ozlabs.org
Cc: linux-mm@kvack•org
Cc: linux-kernel@vger•kernel.org
Tested-by: Jia He <justin.he@arm•com>
Suggested-by: Robin Murphy <robin.murphy@arm•com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm•com>
---
arch/arm64/mm/mmu.c | 3 ++-
arch/powerpc/mm/init_64.c | 10 +++++-----
arch/x86/mm/init_64.c | 6 ++----
include/linux/mm.h | 3 ++-
mm/sparse-vmemmap.c | 30 ++++++++++++++++++++++++------
5 files changed, 35 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 0adad8859393..7ca21adb4412 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1100,7 +1100,8 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
if (pmd_none(READ_ONCE(*pmdp))) {
void *p = NULL;
- p = vmemmap_alloc_block_buf(PMD_SIZE, node);
+ p = vmemmap_alloc_block_buf(PMD_SIZE, node,
+ NULL, false);
if (!p)
return -ENOMEM;
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index bc73abf0bc25..01e25b56eccb 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -225,12 +225,12 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
* fall back to system memory if the altmap allocation fail.
*/
if (altmap && !altmap_cross_boundary(altmap, start, page_size)) {
- p = altmap_alloc_block_buf(page_size, altmap);
- if (!p)
- pr_debug("altmap block allocation failed, falling back to system memory");
+ p = vmemmap_alloc_block_buf(page_size, node,
+ altmap, true);
+ } else {
+ p = vmemmap_alloc_block_buf(page_size, node,
+ NULL, false);
}
- if (!p)
- p = vmemmap_alloc_block_buf(page_size, node);
if (!p)
return -ENOMEM;
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 19c0ed3271a3..4ae4f767c004 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1463,10 +1463,8 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start,
if (pmd_none(*pmd)) {
void *p;
- if (altmap)
- p = altmap_alloc_block_buf(PMD_SIZE, altmap);
- else
- p = vmemmap_alloc_block_buf(PMD_SIZE, node);
+ p = vmemmap_alloc_block_buf(PMD_SIZE, node,
+ altmap, false);
if (p) {
pte_t entry;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e40ac543d248..dade7c3f634d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3015,7 +3015,8 @@ pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
struct vmem_altmap *altmap);
void *vmemmap_alloc_block(unsigned long size, int node);
struct vmem_altmap;
-void *vmemmap_alloc_block_buf(unsigned long size, int node);
+void *vmemmap_alloc_block_buf(unsigned long size, int node,
+ struct vmem_altmap *altmap, bool sysram_fallback);
void *altmap_alloc_block_buf(unsigned long size, struct vmem_altmap *altmap);
void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
int vmemmap_populate_basepages(unsigned long start, unsigned long end,
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index ceed10dec31e..388121c5bbcb 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -70,10 +70,31 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
}
/* need to make sure size is all the same during early stage */
-void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
+void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node,
+ struct vmem_altmap *altmap,
+ bool sysram_fallback)
{
- void *ptr = sparse_buffer_alloc(size);
+ void *ptr;
+ /*
+ * There is no point in asking for sysram fallback
+ * without an altmap request to begin with. So just
+ * warn here to catch potential call sites that may
+ * be violating this.
+ */
+ WARN_ON(!altmap && sysram_fallback);
+
+ if (altmap) {
+ ptr = altmap_alloc_block_buf(size, altmap);
+ if (ptr)
+ return ptr;
+ pr_debug("altmap block allocation failed\n");
+ if (!sysram_fallback)
+ return NULL;
+ pr_debug("falling back to system memory\n");
+ }
+
+ ptr = sparse_buffer_alloc(size);
if (!ptr)
ptr = vmemmap_alloc_block(size, node);
return ptr;
@@ -147,10 +168,7 @@ pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
pte_t entry;
void *p;
- if (altmap)
- p = altmap_alloc_block_buf(PAGE_SIZE, altmap);
- else
- p = vmemmap_alloc_block_buf(PAGE_SIZE, node);
+ p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap, false);
if (!p)
return NULL;
entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
--
2.20.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory
2020-06-18 1:15 [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory Anshuman Khandual
2020-06-18 1:15 ` [PATCH V3 (RESEND) 2/3] mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf() Anshuman Khandual
@ 2020-06-18 8:56 ` Mike Rapoport
2020-06-19 1:34 ` Anshuman Khandual
2020-06-23 7:39 ` Jia He
2 siblings, 1 reply; 8+ messages in thread
From: Mike Rapoport @ 2020-06-18 8:56 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Mark Rutland, Michal Hocko, linux-ia64, David Hildenbrand,
Peter Zijlstra, Dave Hansen, linux-mm, Paul Mackerras,
linux-riscv, Will Deacon, Thomas Gleixner, x86,
Matthew Wilcox (Oracle), Ingo Molnar, Catalin Marinas, Fenghua Yu,
Pavel Tatashin, Andy Lutomirski, Paul Walmsley, Dan Williams,
linux-arm-kernel, Tony Luck, linux-kernel, Palmer Dabbelt,
Andrew Morton, linuxppc-dev, Kirill A. Shutemov
On Thu, Jun 18, 2020 at 06:45:27AM +0530, Anshuman Khandual wrote:
> This series enables vmemmap backing memory allocation from device memory
> ranges on arm64. But before that, it enables vmemmap_populate_basepages()
> and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based
> alocation requests.
>
> This series applies on 5.8-rc1.
>
> Pending Question:
>
> altmap_alloc_block_buf() does not have any other remaining users in
> the tree after this change. Should it be converted into a static
> function and it's declaration be dropped from the header
> (include/linux/mm.h). Avoided doing so because I was not sure if there
> are any off-tree users or not.
Well, off-tree users probably have an active fork anyway so they could
switch to vmemmap_alloc_block_buf()...
Regardless, can you please update Documentation/vm/memory-model.rst to
keep it in sync with the code?
> Changes in V3:
>
> - Dropped comment from free_hotplug_page_range() per Robin
> - Modified comment in unmap_hotplug_range() per Robin
> - Enabled altmap support in vmemmap_alloc_block_buf() per Robin
>
> Changes in V2: (https://lkml.org/lkml/2020/3/4/475)
>
> - Rebased on latest hot-remove series (v14) adding P4D page table support
>
> Changes in V1: (https://lkml.org/lkml/2020/1/23/12)
>
> - Added an WARN_ON() in unmap_hotplug_range() when altmap is
> provided without the page table backing memory being freed
>
> Changes in RFC V2: (https://lkml.org/lkml/2019/10/21/11)
>
> - Changed the commit message on 1/2 patch per Will
> - Changed the commit message on 2/2 patch as well
> - Rebased on arm64 memory hot remove series (v10)
>
> RFC V1: (https://lkml.org/lkml/2019/6/28/32)
>
> Cc: Catalin Marinas <catalin.marinas@arm•com>
> Cc: Will Deacon <will@kernel•org>
> Cc: Mark Rutland <mark.rutland@arm•com>
> Cc: Paul Walmsley <paul.walmsley@sifive•com>
> Cc: Palmer Dabbelt <palmer@dabbelt•com>
> Cc: Tony Luck <tony.luck@intel•com>
> Cc: Fenghua Yu <fenghua.yu@intel•com>
> Cc: Dave Hansen <dave.hansen@linux•intel.com>
> Cc: Andy Lutomirski <luto@kernel•org>
> Cc: Peter Zijlstra <peterz@infradead•org>
> Cc: Thomas Gleixner <tglx@linutronix•de>
> Cc: Ingo Molnar <mingo@redhat•com>
> Cc: David Hildenbrand <david@redhat•com>
> Cc: Mike Rapoport <rppt@linux•ibm.com>
> Cc: Michal Hocko <mhocko@suse•com>
> Cc: "Matthew Wilcox (Oracle)" <willy@infradead•org>
> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux•intel.com>
> Cc: Andrew Morton <akpm@linux-foundation•org>
> Cc: Dan Williams <dan.j.williams@intel•com>
> Cc: Pavel Tatashin <pasha.tatashin@soleen•com>
> Cc: Benjamin Herrenschmidt <benh@kernel•crashing.org>
> Cc: Paul Mackerras <paulus@samba•org>
> Cc: Michael Ellerman <mpe@ellerman•id.au>
> Cc: linux-arm-kernel@lists•infradead.org
> Cc: linux-ia64@vger•kernel.org
> Cc: linux-riscv@lists•infradead.org
> Cc: x86@kernel•org
> Cc: linuxppc-dev@lists•ozlabs.org
> Cc: linux-mm@kvack•org
> Cc: linux-kernel@vger•kernel.org
>
> Anshuman Khandual (3):
> mm/sparsemem: Enable vmem_altmap support in vmemmap_populate_basepages()
> mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf()
> arm64/mm: Enable vmem_altmap support for vmemmap mappings
>
> arch/arm64/mm/mmu.c | 59 ++++++++++++++++++++++++++-------------
> arch/ia64/mm/discontig.c | 2 +-
> arch/powerpc/mm/init_64.c | 10 +++----
> arch/riscv/mm/init.c | 2 +-
> arch/x86/mm/init_64.c | 12 ++++----
> include/linux/mm.h | 8 ++++--
> mm/sparse-vmemmap.c | 38 ++++++++++++++++++++-----
> 7 files changed, 87 insertions(+), 44 deletions(-)
>
> --
> 2.20.1
>
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory
2020-06-18 1:15 [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory Anshuman Khandual
2020-06-18 1:15 ` [PATCH V3 (RESEND) 2/3] mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf() Anshuman Khandual
2020-06-18 8:56 ` [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory Mike Rapoport
@ 2020-06-23 7:39 ` Jia He
2 siblings, 0 replies; 8+ messages in thread
From: Jia He @ 2020-06-23 7:39 UTC (permalink / raw)
To: Anshuman Khandual, linux-mm
Cc: Mark Rutland, Michal Hocko, linux-ia64, David Hildenbrand,
Peter Zijlstra, Dave Hansen, Paul Mackerras, linux-riscv,
Will Deacon, Thomas Gleixner, x86, Matthew Wilcox (Oracle),
Mike Rapoport, Ingo Molnar, Catalin Marinas, Fenghua Yu,
Pavel Tatashin, Andy Lutomirski, Paul Walmsley, Dan Williams,
linux-arm-kernel, Tony Luck, linux-kernel, Palmer Dabbelt,
Andrew Morton, linuxppc-dev, Kirill A. Shutemov
[-- Attachment #1: Type: text/plain, Size: 4271 bytes --]
Hi
I also tested the addional cases on arm64
1, 4k page size + devdax + --map=mem
2, 64k page size + devdax + --map=mem
3, 4k page size + devdax + --map=dev
4, 64k page size + devdax + --map=dev
case 4 is important to verify Anshuman's this series.
Host kernel: 5.7-rc3
guest kernel: 5.7-rc5 with this series
ndctl: https://github.com/pmem/ndctl/tree/c7767834871
<https://github.com/pmem/ndctl/tree/c7767834871f7ce50a2abe1da946e9e16fb08eda>
On the guest:
1. ./ndctl/.libs/ndctl create-namespace -e namespace0.0 --mode=devdax --map=dev
-s 1g -f -v -a 64K
echo dax0.0 > /sys/bus/dax/drivers/device_dax/unbind
echo dax0.0 > /sys/bus/dax/drivers/kmem/new_id
The 1g block was added
2. echo 0 > /sys/devices/system/memory/memory10/online
modprobe -r dax_pmem
The 1g block was removed
Some minor fix should be applied which is not relevant to this series itself.
e.g numa id
---
Cheers,
Justin (Jia He)
On 2020/6/18 9:15, Anshuman Khandual wrote:
> This series enables vmemmap backing memory allocation from device memory
> ranges on arm64. But before that, it enables vmemmap_populate_basepages()
> and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based
> alocation requests.
>
> This series applies on 5.8-rc1.
>
> Pending Question:
>
> altmap_alloc_block_buf() does not have any other remaining users in the
> tree after this change. Should it be converted into a static function and
> it's declaration be dropped from the header (include/linux/mm.h). Avoided
> doing so because I was not sure if there are any off-tree users or not.
>
> Changes in V3:
>
> - Dropped comment from free_hotplug_page_range() per Robin
> - Modified comment in unmap_hotplug_range() per Robin
> - Enabled altmap support in vmemmap_alloc_block_buf() per Robin
>
> Changes in V2: (https://lkml.org/lkml/2020/3/4/475)
>
> - Rebased on latest hot-remove series (v14) adding P4D page table support
>
> Changes in V1: (https://lkml.org/lkml/2020/1/23/12)
>
> - Added an WARN_ON() in unmap_hotplug_range() when altmap is
> provided without the page table backing memory being freed
>
> Changes in RFC V2: (https://lkml.org/lkml/2019/10/21/11)
>
> - Changed the commit message on 1/2 patch per Will
> - Changed the commit message on 2/2 patch as well
> - Rebased on arm64 memory hot remove series (v10)
>
> RFC V1: (https://lkml.org/lkml/2019/6/28/32)
>
> Cc: Catalin Marinas <catalin.marinas@arm•com>
> Cc: Will Deacon <will@kernel•org>
> Cc: Mark Rutland <mark.rutland@arm•com>
> Cc: Paul Walmsley <paul.walmsley@sifive•com>
> Cc: Palmer Dabbelt <palmer@dabbelt•com>
> Cc: Tony Luck <tony.luck@intel•com>
> Cc: Fenghua Yu <fenghua.yu@intel•com>
> Cc: Dave Hansen <dave.hansen@linux•intel.com>
> Cc: Andy Lutomirski <luto@kernel•org>
> Cc: Peter Zijlstra <peterz@infradead•org>
> Cc: Thomas Gleixner <tglx@linutronix•de>
> Cc: Ingo Molnar <mingo@redhat•com>
> Cc: David Hildenbrand <david@redhat•com>
> Cc: Mike Rapoport <rppt@linux•ibm.com>
> Cc: Michal Hocko <mhocko@suse•com>
> Cc: "Matthew Wilcox (Oracle)" <willy@infradead•org>
> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux•intel.com>
> Cc: Andrew Morton <akpm@linux-foundation•org>
> Cc: Dan Williams <dan.j.williams@intel•com>
> Cc: Pavel Tatashin <pasha.tatashin@soleen•com>
> Cc: Benjamin Herrenschmidt <benh@kernel•crashing.org>
> Cc: Paul Mackerras <paulus@samba•org>
> Cc: Michael Ellerman <mpe@ellerman•id.au>
> Cc: linux-arm-kernel@lists•infradead.org
> Cc: linux-ia64@vger•kernel.org
> Cc: linux-riscv@lists•infradead.org
> Cc: x86@kernel•org
> Cc: linuxppc-dev@lists•ozlabs.org
> Cc: linux-mm@kvack•org
> Cc: linux-kernel@vger•kernel.org
>
> Anshuman Khandual (3):
> mm/sparsemem: Enable vmem_altmap support in vmemmap_populate_basepages()
> mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf()
> arm64/mm: Enable vmem_altmap support for vmemmap mappings
>
> arch/arm64/mm/mmu.c | 59 ++++++++++++++++++++++++++-------------
> arch/ia64/mm/discontig.c | 2 +-
> arch/powerpc/mm/init_64.c | 10 +++----
> arch/riscv/mm/init.c | 2 +-
> arch/x86/mm/init_64.c | 12 ++++----
> include/linux/mm.h | 8 ++++--
> mm/sparse-vmemmap.c | 38 ++++++++++++++++++++-----
> 7 files changed, 87 insertions(+), 44 deletions(-)
>
--
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^ permalink raw reply [flat|nested] 8+ messages in thread