* [PATCH -V2 1/5] powerpc: Use HPTE constants when updating hpte bits
2013-11-18 9:28 [PATCH -V2 0/5] powerpc: mm: Numa faults support for ppc64 Aneesh Kumar K.V
@ 2013-11-18 9:28 ` Aneesh Kumar K.V
2013-11-20 4:35 ` Paul Mackerras
2013-11-18 9:28 ` [PATCH -V2 2/5] powerpc: Free up _PAGE_COHERENCE for numa fault use later Aneesh Kumar K.V
` (3 subsequent siblings)
4 siblings, 1 reply; 16+ messages in thread
From: Aneesh Kumar K.V @ 2013-11-18 9:28 UTC (permalink / raw)
To: benh, paulus, linux-mm; +Cc: linuxppc-dev, Aneesh Kumar K.V
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Even though we have same value for linux PTE bits and hash PTE pits
use the hash pte bits wen updating hash pte
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/platforms/cell/beat_htab.c | 4 ++--
arch/powerpc/platforms/pseries/lpar.c | 3 ++-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/cell/beat_htab.c b/arch/powerpc/platforms/cell/beat_htab.c
index c34ee4e60873..d4d245c0d787 100644
--- a/arch/powerpc/platforms/cell/beat_htab.c
+++ b/arch/powerpc/platforms/cell/beat_htab.c
@@ -111,7 +111,7 @@ static long beat_lpar_hpte_insert(unsigned long hpte_group,
DBG_LOW(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);
if (rflags & _PAGE_NO_CACHE)
- hpte_r &= ~_PAGE_COHERENT;
+ hpte_r &= ~HPTE_R_M;
raw_spin_lock(&beat_htab_lock);
lpar_rc = beat_read_mask(hpte_group);
@@ -337,7 +337,7 @@ static long beat_lpar_hpte_insert_v3(unsigned long hpte_group,
DBG_LOW(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);
if (rflags & _PAGE_NO_CACHE)
- hpte_r &= ~_PAGE_COHERENT;
+ hpte_r &= ~HPTE_R_M;
/* insert into not-volted entry */
lpar_rc = beat_insert_htab_entry3(0, hpte_group, hpte_v, hpte_r,
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 356bc75ca74f..c8fbef238d4b 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -153,7 +153,8 @@ static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
/* Make pHyp happy */
if ((rflags & _PAGE_NO_CACHE) && !(rflags & _PAGE_WRITETHRU))
- hpte_r &= ~_PAGE_COHERENT;
+ hpte_r &= ~HPTE_R_M;
+
if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
flags |= H_COALESCE_CAND;
--
1.8.3.2
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^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH -V2 1/5] powerpc: Use HPTE constants when updating hpte bits
2013-11-18 9:28 ` [PATCH -V2 1/5] powerpc: Use HPTE constants when updating hpte bits Aneesh Kumar K.V
@ 2013-11-20 4:35 ` Paul Mackerras
0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2013-11-20 4:35 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: benh, linux-mm, linuxppc-dev
On Mon, Nov 18, 2013 at 02:58:09PM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> Even though we have same value for linux PTE bits and hash PTE pits
bits, not pits :)
> use the hash pte bits wen updating hash pte
when, not wen
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
If you fix the spelling errors in the patch description:
Acked-by: Paul Mackerras <paulus@samba.org>
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^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH -V2 2/5] powerpc: Free up _PAGE_COHERENCE for numa fault use later
2013-11-18 9:28 [PATCH -V2 0/5] powerpc: mm: Numa faults support for ppc64 Aneesh Kumar K.V
2013-11-18 9:28 ` [PATCH -V2 1/5] powerpc: Use HPTE constants when updating hpte bits Aneesh Kumar K.V
@ 2013-11-18 9:28 ` Aneesh Kumar K.V
2013-11-20 4:35 ` Paul Mackerras
2013-11-18 9:28 ` [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE Aneesh Kumar K.V
` (2 subsequent siblings)
4 siblings, 1 reply; 16+ messages in thread
From: Aneesh Kumar K.V @ 2013-11-18 9:28 UTC (permalink / raw)
To: benh, paulus, linux-mm; +Cc: linuxppc-dev, Aneesh Kumar K.V
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Set memory coherence always on hash64 config. If
a platform cannot have memory coherence always set they
can infer that from _PAGE_NO_CACHE and _PAGE_WRITETHRU
like in lpar. So we dont' really need a separate bit
for tracking _PAGE_COHERENCE.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/pte-hash64.h | 2 +-
arch/powerpc/mm/hash_low_64.S | 15 ++++++++++++---
arch/powerpc/mm/hash_utils_64.c | 7 ++++---
arch/powerpc/mm/hugepage-hash64.c | 6 +++++-
arch/powerpc/mm/hugetlbpage-hash64.c | 4 ++++
5 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/pte-hash64.h b/arch/powerpc/include/asm/pte-hash64.h
index 0419eeb53274..55aea0caf95e 100644
--- a/arch/powerpc/include/asm/pte-hash64.h
+++ b/arch/powerpc/include/asm/pte-hash64.h
@@ -19,7 +19,7 @@
#define _PAGE_FILE 0x0002 /* (!present only) software: pte holds file offset */
#define _PAGE_EXEC 0x0004 /* No execute on POWER4 and newer (we invert) */
#define _PAGE_GUARDED 0x0008
-#define _PAGE_COHERENT 0x0010 /* M: enforce memory coherence (SMP systems) */
+/* We can derive Memory coherence from _PAGE_NO_CACHE */
#define _PAGE_NO_CACHE 0x0020 /* I: cache inhibit */
#define _PAGE_WRITETHRU 0x0040 /* W: cache write-through */
#define _PAGE_DIRTY 0x0080 /* C: page changed */
diff --git a/arch/powerpc/mm/hash_low_64.S b/arch/powerpc/mm/hash_low_64.S
index d3cbda62857b..1136d26a95ae 100644
--- a/arch/powerpc/mm/hash_low_64.S
+++ b/arch/powerpc/mm/hash_low_64.S
@@ -148,7 +148,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
and r0,r0,r4 /* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
andc r0,r30,r0 /* r0 = pte & ~r0 */
rlwimi r3,r0,32-1,31,31 /* Insert result into PP lsb */
- ori r3,r3,HPTE_R_C /* Always add "C" bit for perf. */
+ /*
+ * Always add "C" bit for perf. Memory coherence is always enabled
+ */
+ ori r3,r3,HPTE_R_C | HPTE_R_M
/* We eventually do the icache sync here (maybe inline that
* code rather than call a C function...)
@@ -457,7 +460,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
and r0,r0,r4 /* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
andc r0,r3,r0 /* r0 = pte & ~r0 */
rlwimi r3,r0,32-1,31,31 /* Insert result into PP lsb */
- ori r3,r3,HPTE_R_C /* Always add "C" bit for perf. */
+ /*
+ * Always add "C" bit for perf. Memory coherence is always enabled
+ */
+ ori r3,r3,HPTE_R_C | HPTE_R_M
/* We eventually do the icache sync here (maybe inline that
* code rather than call a C function...)
@@ -795,7 +801,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
and r0,r0,r4 /* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
andc r0,r30,r0 /* r0 = pte & ~r0 */
rlwimi r3,r0,32-1,31,31 /* Insert result into PP lsb */
- ori r3,r3,HPTE_R_C /* Always add "C" bit for perf. */
+ /*
+ * Always add "C" bit for perf. Memory coherence is always enabled
+ */
+ ori r3,r3,HPTE_R_C | HPTE_R_M
/* We eventually do the icache sync here (maybe inline that
* code rather than call a C function...)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 6176b3cdf579..de6881259aef 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -169,9 +169,10 @@ static unsigned long htab_convert_pte_flags(unsigned long pteflags)
if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) &&
(pteflags & _PAGE_DIRTY)))
rflags |= 1;
-
- /* Always add C */
- return rflags | HPTE_R_C;
+ /*
+ * Always add "C" bit for perf. Memory coherence is always enabled
+ */
+ return rflags | HPTE_R_C | HPTE_R_M;
}
int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index 34de9e0cdc34..826893fcb3a7 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -127,7 +127,11 @@ repeat:
/* Add in WIMG bits */
rflags |= (new_pmd & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
- _PAGE_COHERENT | _PAGE_GUARDED));
+ _PAGE_GUARDED));
+ /*
+ * enable the memory coherence always
+ */
+ rflags |= HPTE_R_M;
/* Insert into the hash table, primary slot */
slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0,
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 0b7fb6761015..a5bcf9301196 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -99,6 +99,10 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
/* Add in WIMG bits */
rflags |= (new_pte & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
_PAGE_COHERENT | _PAGE_GUARDED));
+ /*
+ * enable the memory coherence always
+ */
+ rflags |= HPTE_R_M;
slot = hpte_insert_repeating(hash, vpn, pa, rflags, 0,
mmu_psize, ssize);
--
1.8.3.2
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^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH -V2 2/5] powerpc: Free up _PAGE_COHERENCE for numa fault use later
2013-11-18 9:28 ` [PATCH -V2 2/5] powerpc: Free up _PAGE_COHERENCE for numa fault use later Aneesh Kumar K.V
@ 2013-11-20 4:35 ` Paul Mackerras
0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2013-11-20 4:35 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: benh, linux-mm, linuxppc-dev
On Mon, Nov 18, 2013 at 02:58:10PM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> Set memory coherence always on hash64 config. If
> a platform cannot have memory coherence always set they
> can infer that from _PAGE_NO_CACHE and _PAGE_WRITETHRU
> like in lpar. So we dont' really need a separate bit
> for tracking _PAGE_COHERENCE.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
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^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-11-18 9:28 [PATCH -V2 0/5] powerpc: mm: Numa faults support for ppc64 Aneesh Kumar K.V
2013-11-18 9:28 ` [PATCH -V2 1/5] powerpc: Use HPTE constants when updating hpte bits Aneesh Kumar K.V
2013-11-18 9:28 ` [PATCH -V2 2/5] powerpc: Free up _PAGE_COHERENCE for numa fault use later Aneesh Kumar K.V
@ 2013-11-18 9:28 ` Aneesh Kumar K.V
2013-12-04 3:13 ` Benjamin Herrenschmidt
2013-11-18 9:28 ` [PATCH -V2 4/5] powerpc: mm: Only check for _PAGE_PRESENT in set_pte/pmd functions Aneesh Kumar K.V
2013-11-18 9:28 ` [PATCH -V2 5/5] powerpc: mm: book3s: Enable _PAGE_NUMA for book3s Aneesh Kumar K.V
4 siblings, 1 reply; 16+ messages in thread
From: Aneesh Kumar K.V @ 2013-11-18 9:28 UTC (permalink / raw)
To: benh, paulus, linux-mm; +Cc: linuxppc-dev, Aneesh Kumar K.V
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
change_prot_numa should work even if _PAGE_NUMA != _PAGE_PROTNONE.
On archs like ppc64 that don't use _PAGE_PROTNONE and also have
a separate page table outside linux pagetable, we just need to
make sure that when calling change_prot_numa we flush the
hardware page table entry so that next page access result in a numa
fault.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
include/linux/mm.h | 3 ---
mm/mempolicy.c | 9 ---------
2 files changed, 12 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0548eb201e05..51794c1a1d7e 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1851,11 +1851,8 @@ static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
}
#endif
-#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
unsigned long change_prot_numa(struct vm_area_struct *vma,
unsigned long start, unsigned long end);
-#endif
-
struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
unsigned long pfn, unsigned long size, pgprot_t);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index c4403cdf3433..cae10af4fdc4 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -613,7 +613,6 @@ static inline int queue_pages_pgd_range(struct vm_area_struct *vma,
return 0;
}
-#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
/*
* This is used to mark a range of virtual addresses to be inaccessible.
* These are later cleared by a NUMA hinting fault. Depending on these
@@ -627,7 +626,6 @@ unsigned long change_prot_numa(struct vm_area_struct *vma,
unsigned long addr, unsigned long end)
{
int nr_updated;
- BUILD_BUG_ON(_PAGE_NUMA != _PAGE_PROTNONE);
nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1);
if (nr_updated)
@@ -635,13 +633,6 @@ unsigned long change_prot_numa(struct vm_area_struct *vma,
return nr_updated;
}
-#else
-static unsigned long change_prot_numa(struct vm_area_struct *vma,
- unsigned long addr, unsigned long end)
-{
- return 0;
-}
-#endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */
/*
* Walk through page tables and collect pages to be migrated.
--
1.8.3.2
--
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^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-11-18 9:28 ` [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE Aneesh Kumar K.V
@ 2013-12-04 3:13 ` Benjamin Herrenschmidt
2013-12-05 5:18 ` Aneesh Kumar K.V
2013-12-05 17:27 ` Rik van Riel
0 siblings, 2 replies; 16+ messages in thread
From: Benjamin Herrenschmidt @ 2013-12-04 3:13 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: paulus, linux-mm, linuxppc-dev
On Mon, 2013-11-18 at 14:58 +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> change_prot_numa should work even if _PAGE_NUMA != _PAGE_PROTNONE.
> On archs like ppc64 that don't use _PAGE_PROTNONE and also have
> a separate page table outside linux pagetable, we just need to
> make sure that when calling change_prot_numa we flush the
> hardware page table entry so that next page access result in a numa
> fault.
That patch doesn't look right...
You are essentially making change_prot_numa() do whatever it does (which
I don't completely understand) *for all architectures* now, whether they
have CONFIG_ARCH_USES_NUMA_PROT_NONE or not ... So because you want that
behaviour on powerpc book3s64, you change everybody.
Is that correct ?
Also what exactly is that doing, can you explain ? From what I can see,
it calls back into the core of mprotect to change the protection to
vma->vm_page_prot, which I would have expected is already the protection
there, with the added "prot_numa" flag passed down.
Your changeset comment says "On archs like ppc64 [...] we just need to
make sure that when calling change_prot_numa we flush the
hardware page table entry so that next page access result in a numa
fault."
But change_prot_numa() does a lot more than that ... it does
pte_mknuma(), do we need it ? I assume we do or we wouldn't have added
that PTE bit to begin with...
Now it *might* be allright and it might be that no other architecture
cares anyway etc... but I need at least some mm folks to ack on that
patch before I can take it because it *will* change behaviour of other
architectures.
Cheers,
Ben.
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> include/linux/mm.h | 3 ---
> mm/mempolicy.c | 9 ---------
> 2 files changed, 12 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 0548eb201e05..51794c1a1d7e 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1851,11 +1851,8 @@ static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
> }
> #endif
>
> -#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
> unsigned long change_prot_numa(struct vm_area_struct *vma,
> unsigned long start, unsigned long end);
> -#endif
> -
> struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
> int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
> unsigned long pfn, unsigned long size, pgprot_t);
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index c4403cdf3433..cae10af4fdc4 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -613,7 +613,6 @@ static inline int queue_pages_pgd_range(struct vm_area_struct *vma,
> return 0;
> }
>
> -#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
> /*
> * This is used to mark a range of virtual addresses to be inaccessible.
> * These are later cleared by a NUMA hinting fault. Depending on these
> @@ -627,7 +626,6 @@ unsigned long change_prot_numa(struct vm_area_struct *vma,
> unsigned long addr, unsigned long end)
> {
> int nr_updated;
> - BUILD_BUG_ON(_PAGE_NUMA != _PAGE_PROTNONE);
>
> nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1);
> if (nr_updated)
> @@ -635,13 +633,6 @@ unsigned long change_prot_numa(struct vm_area_struct *vma,
>
> return nr_updated;
> }
> -#else
> -static unsigned long change_prot_numa(struct vm_area_struct *vma,
> - unsigned long addr, unsigned long end)
> -{
> - return 0;
> -}
> -#endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */
>
> /*
> * Walk through page tables and collect pages to be migrated.
--
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^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-12-04 3:13 ` Benjamin Herrenschmidt
@ 2013-12-05 5:18 ` Aneesh Kumar K.V
2013-12-05 5:20 ` Benjamin Herrenschmidt
2013-12-05 17:27 ` Rik van Riel
1 sibling, 1 reply; 16+ messages in thread
From: Aneesh Kumar K.V @ 2013-12-05 5:18 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Mel Gorman, Rik van Riel
Cc: paulus, linux-mm, linuxppc-dev
Adding Mel and Rik to cc:
Benjamin Herrenschmidt <benh@au1.ibm.com> writes:
> On Mon, 2013-11-18 at 14:58 +0530, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>>
>> change_prot_numa should work even if _PAGE_NUMA != _PAGE_PROTNONE.
>> On archs like ppc64 that don't use _PAGE_PROTNONE and also have
>> a separate page table outside linux pagetable, we just need to
>> make sure that when calling change_prot_numa we flush the
>> hardware page table entry so that next page access result in a numa
>> fault.
>
> That patch doesn't look right...
>
> You are essentially making change_prot_numa() do whatever it does (which
> I don't completely understand) *for all architectures* now, whether they
> have CONFIG_ARCH_USES_NUMA_PROT_NONE or not ... So because you want that
> behaviour on powerpc book3s64, you change everybody.
>
> Is that correct ?
Yes.
>
> Also what exactly is that doing, can you explain ? From what I can see,
> it calls back into the core of mprotect to change the protection to
> vma->vm_page_prot, which I would have expected is already the protection
> there, with the added "prot_numa" flag passed down.
it set the _PAGE_NUMA bit. Now we also want to make sure that when
we set _PAGE_NUMA, we would get a pagefault on that so that we can track
that fault as a numa fault. To ensure that, we had the below BUILD_BUG
BUILD_BUG_ON(_PAGE_NUMA != _PAGE_PROTNONE);
But other than that the function doesn't really have any dependency on
_PAGE_PROTNONE. The only requirement is when we set _PAGE_NUMA, the
architecture should do enough to ensure that we get a page fault. Now on
ppc64 we does that by clearlying hpte entry and also clearing
_PAGE_PRESENT. Since we have _PAGE_PRESENT cleared hash_page will return
1 and we get to page fault handler.
>
> Your changeset comment says "On archs like ppc64 [...] we just need to
> make sure that when calling change_prot_numa we flush the
> hardware page table entry so that next page access result in a numa
> fault."
>
> But change_prot_numa() does a lot more than that ... it does
> pte_mknuma(), do we need it ? I assume we do or we wouldn't have added
> that PTE bit to begin with...
>
> Now it *might* be allright and it might be that no other architecture
> cares anyway etc... but I need at least some mm folks to ack on that
> patch before I can take it because it *will* change behaviour of other
> architectures.
>
Ok, I can move the changes below #ifdef CONFIG_NUMA_BALANCING ? We call
change_prot_numa from task_numa_work and queue_pages_range(). The later
may be an issue. So doing the below will help ?
-#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
+#ifdef CONFIG_NUMA_BALANCING
-aneesh
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^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-12-05 5:18 ` Aneesh Kumar K.V
@ 2013-12-05 5:20 ` Benjamin Herrenschmidt
2013-12-05 17:52 ` Rik van Riel
0 siblings, 1 reply; 16+ messages in thread
From: Benjamin Herrenschmidt @ 2013-12-05 5:20 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: Mel Gorman, Rik van Riel, paulus, linux-mm, linuxppc-dev
On Thu, 2013-12-05 at 10:48 +0530, Aneesh Kumar K.V wrote:
>
> Ok, I can move the changes below #ifdef CONFIG_NUMA_BALANCING ? We call
> change_prot_numa from task_numa_work and queue_pages_range(). The later
> may be an issue. So doing the below will help ?
>
> -#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
> +#ifdef CONFIG_NUMA_BALANCING
I will defer to Mel and Rik (should we also CC Andrea ?)
Cheers,
Ben.
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^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-12-05 5:20 ` Benjamin Herrenschmidt
@ 2013-12-05 17:52 ` Rik van Riel
0 siblings, 0 replies; 16+ messages in thread
From: Rik van Riel @ 2013-12-05 17:52 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Aneesh Kumar K.V
Cc: Mel Gorman, paulus, linux-mm, linuxppc-dev
On 12/05/2013 12:20 AM, Benjamin Herrenschmidt wrote:
> On Thu, 2013-12-05 at 10:48 +0530, Aneesh Kumar K.V wrote:
>>
>> Ok, I can move the changes below #ifdef CONFIG_NUMA_BALANCING ? We call
>> change_prot_numa from task_numa_work and queue_pages_range(). The later
>> may be an issue. So doing the below will help ?
>>
>> -#ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
>> +#ifdef CONFIG_NUMA_BALANCING
>
> I will defer to Mel and Rik (should we also CC Andrea ?)
It looks like manual numa binding can also use lazy
page migration, but I am not sure if that can happen
without CONFIG_NUMA_BALANCING, or if mbind always uses
MPOL_MF_STRICT...
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^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-12-04 3:13 ` Benjamin Herrenschmidt
2013-12-05 5:18 ` Aneesh Kumar K.V
@ 2013-12-05 17:27 ` Rik van Riel
2013-12-05 21:00 ` Benjamin Herrenschmidt
1 sibling, 1 reply; 16+ messages in thread
From: Rik van Riel @ 2013-12-05 17:27 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Aneesh Kumar K.V; +Cc: paulus, linux-mm, linuxppc-dev
On 12/03/2013 10:13 PM, Benjamin Herrenschmidt wrote:
> On Mon, 2013-11-18 at 14:58 +0530, Aneesh Kumar K.V wrote:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>>
>> change_prot_numa should work even if _PAGE_NUMA != _PAGE_PROTNONE.
>> On archs like ppc64 that don't use _PAGE_PROTNONE and also have
>> a separate page table outside linux pagetable, we just need to
>> make sure that when calling change_prot_numa we flush the
>> hardware page table entry so that next page access result in a numa
>> fault.
>
> That patch doesn't look right...
At first glance, indeed...
> You are essentially making change_prot_numa() do whatever it does (which
> I don't completely understand) *for all architectures* now, whether they
> have CONFIG_ARCH_USES_NUMA_PROT_NONE or not ... So because you want that
> behaviour on powerpc book3s64, you change everybody.
However, it appears that since the code was #ifdefed
like that, the called code was made generic enough,
that change_prot_numa should actually work for
everything.
In other words:
Reviewed-by: Rik van Riel <riel@redhat.com>
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^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE
2013-12-05 17:27 ` Rik van Riel
@ 2013-12-05 21:00 ` Benjamin Herrenschmidt
0 siblings, 0 replies; 16+ messages in thread
From: Benjamin Herrenschmidt @ 2013-12-05 21:00 UTC (permalink / raw)
To: Rik van Riel; +Cc: Aneesh Kumar K.V, paulus, linux-mm, linuxppc-dev
On Thu, 2013-12-05 at 12:27 -0500, Rik van Riel wrote:
> However, it appears that since the code was #ifdefed
> like that, the called code was made generic enough,
> that change_prot_numa should actually work for
> everything.
>
> In other words:
>
> Reviewed-by: Rik van Riel <riel@redhat.com>
Ok thanks, that's what I needed. Do you have any objection of me merging
that change via the powerpc tree along with the corresponding powerpc
bits from Aneesh ?
The other option would be to have it in a topic branch that I pull from
you.
Cheers,
Ben.
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^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH -V2 4/5] powerpc: mm: Only check for _PAGE_PRESENT in set_pte/pmd functions
2013-11-18 9:28 [PATCH -V2 0/5] powerpc: mm: Numa faults support for ppc64 Aneesh Kumar K.V
` (2 preceding siblings ...)
2013-11-18 9:28 ` [PATCH -V2 3/5] mm: Move change_prot_numa outside CONFIG_ARCH_USES_NUMA_PROT_NONE Aneesh Kumar K.V
@ 2013-11-18 9:28 ` Aneesh Kumar K.V
2013-11-20 4:36 ` Paul Mackerras
2013-11-18 9:28 ` [PATCH -V2 5/5] powerpc: mm: book3s: Enable _PAGE_NUMA for book3s Aneesh Kumar K.V
4 siblings, 1 reply; 16+ messages in thread
From: Aneesh Kumar K.V @ 2013-11-18 9:28 UTC (permalink / raw)
To: benh, paulus, linux-mm; +Cc: linuxppc-dev, Aneesh Kumar K.V
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
We want to make sure we don't use these function when updating a pte
or pmd entry that have a valid hpte entry, because these functions
don't invalidate them. So limit the check to _PAGE_PRESENT bit.
Numafault core changes use these functions for updating _PAGE_NUMA bits.
That should be ok because when _PAGE_NUMA is set we can be sure that
hpte entries are not present.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/mm/pgtable.c | 2 +-
arch/powerpc/mm/pgtable_64.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 841e0d00863c..ad90429bbd8b 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -174,7 +174,7 @@ void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
pte_t pte)
{
#ifdef CONFIG_DEBUG_VM
- WARN_ON(pte_present(*ptep));
+ WARN_ON(pte_val(*ptep) & _PAGE_PRESENT);
#endif
/* Note: mm->context.id might not yet have been assigned as
* this context might not have been activated yet when this
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 9d95786aa80f..02e8681fb865 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -687,7 +687,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
- WARN_ON(!pmd_none(*pmdp));
+ WARN_ON(pmd_val(*pmdp) & _PAGE_PRESENT);
assert_spin_locked(&mm->page_table_lock);
WARN_ON(!pmd_trans_huge(pmd));
#endif
--
1.8.3.2
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^ permalink raw reply related [flat|nested] 16+ messages in thread* Re: [PATCH -V2 4/5] powerpc: mm: Only check for _PAGE_PRESENT in set_pte/pmd functions
2013-11-18 9:28 ` [PATCH -V2 4/5] powerpc: mm: Only check for _PAGE_PRESENT in set_pte/pmd functions Aneesh Kumar K.V
@ 2013-11-20 4:36 ` Paul Mackerras
0 siblings, 0 replies; 16+ messages in thread
From: Paul Mackerras @ 2013-11-20 4:36 UTC (permalink / raw)
To: Aneesh Kumar K.V; +Cc: benh, linux-mm, linuxppc-dev
On Mon, Nov 18, 2013 at 02:58:12PM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> We want to make sure we don't use these function when updating a pte
> or pmd entry that have a valid hpte entry, because these functions
> don't invalidate them. So limit the check to _PAGE_PRESENT bit.
> Numafault core changes use these functions for updating _PAGE_NUMA bits.
> That should be ok because when _PAGE_NUMA is set we can be sure that
> hpte entries are not present.
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
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^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH -V2 5/5] powerpc: mm: book3s: Enable _PAGE_NUMA for book3s
2013-11-18 9:28 [PATCH -V2 0/5] powerpc: mm: Numa faults support for ppc64 Aneesh Kumar K.V
` (3 preceding siblings ...)
2013-11-18 9:28 ` [PATCH -V2 4/5] powerpc: mm: Only check for _PAGE_PRESENT in set_pte/pmd functions Aneesh Kumar K.V
@ 2013-11-18 9:28 ` Aneesh Kumar K.V
2013-11-20 4:37 ` Paul Mackerras
4 siblings, 1 reply; 16+ messages in thread
From: Aneesh Kumar K.V @ 2013-11-18 9:28 UTC (permalink / raw)
To: benh, paulus, linux-mm; +Cc: linuxppc-dev, Aneesh Kumar K.V
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
We steal the _PAGE_COHERENCE bit and use that for indicating NUMA ptes.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/pgtable.h | 66 +++++++++++++++++++++++++++++++++-
arch/powerpc/include/asm/pte-hash64.h | 6 ++++
arch/powerpc/platforms/Kconfig.cputype | 1 +
3 files changed, 72 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 7d6eacf249cf..b999ca318985 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -3,6 +3,7 @@
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
+#include <linux/mmdebug.h>
#include <asm/processor.h> /* For TASK_SIZE */
#include <asm/mmu.h>
#include <asm/page.h>
@@ -33,10 +34,73 @@ static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; }
static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
-static inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_PRESENT; }
static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
+#ifdef CONFIG_NUMA_BALANCING
+
+static inline int pte_present(pte_t pte)
+{
+ return pte_val(pte) & (_PAGE_PRESENT | _PAGE_NUMA);
+}
+
+#define pte_numa pte_numa
+static inline int pte_numa(pte_t pte)
+{
+ return (pte_val(pte) &
+ (_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
+}
+
+#define pte_mknonnuma pte_mknonnuma
+static inline pte_t pte_mknonnuma(pte_t pte)
+{
+ pte_val(pte) &= ~_PAGE_NUMA;
+ pte_val(pte) |= _PAGE_PRESENT | _PAGE_ACCESSED;
+ return pte;
+}
+
+#define pte_mknuma pte_mknuma
+static inline pte_t pte_mknuma(pte_t pte)
+{
+ /*
+ * We should not set _PAGE_NUMA on non present ptes. Also clear the
+ * present bit so that hash_page will return 1 and we collect this
+ * as numa fault.
+ */
+ if (pte_present(pte)) {
+ pte_val(pte) |= _PAGE_NUMA;
+ pte_val(pte) &= ~_PAGE_PRESENT;
+ } else
+ VM_BUG_ON(1);
+ return pte;
+}
+
+#define pmd_numa pmd_numa
+static inline int pmd_numa(pmd_t pmd)
+{
+ return pte_numa(pmd_pte(pmd));
+}
+
+#define pmd_mknonnuma pmd_mknonnuma
+static inline pmd_t pmd_mknonnuma(pmd_t pmd)
+{
+ return pte_pmd(pte_mknonnuma(pmd_pte(pmd)));
+}
+
+#define pmd_mknuma pmd_mknuma
+static inline pmd_t pmd_mknuma(pmd_t pmd)
+{
+ return pte_pmd(pte_mknuma(pmd_pte(pmd)));
+}
+
+# else
+
+static inline int pte_present(pte_t pte)
+{
+ return pte_val(pte) & _PAGE_PRESENT;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
/* Conversion functions: convert a page and protection to a page entry,
* and a page entry and page directory to the page they refer to.
*
diff --git a/arch/powerpc/include/asm/pte-hash64.h b/arch/powerpc/include/asm/pte-hash64.h
index 55aea0caf95e..2505d8eab15c 100644
--- a/arch/powerpc/include/asm/pte-hash64.h
+++ b/arch/powerpc/include/asm/pte-hash64.h
@@ -27,6 +27,12 @@
#define _PAGE_RW 0x0200 /* software: user write access allowed */
#define _PAGE_BUSY 0x0800 /* software: PTE & hash are busy */
+/*
+ * Used for tracking numa faults
+ */
+#define _PAGE_NUMA 0x00000010 /* Gather numa placement stats */
+
+
/* No separate kernel read-only */
#define _PAGE_KERNEL_RW (_PAGE_RW | _PAGE_DIRTY) /* user access blocked by key */
#define _PAGE_KERNEL_RO _PAGE_KERNEL_RW
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index c2a566fb8bb8..2048655d8ec4 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -72,6 +72,7 @@ config PPC_BOOK3S_64
select PPC_HAVE_PMU_SUPPORT
select SYS_SUPPORTS_HUGETLBFS
select HAVE_ARCH_TRANSPARENT_HUGEPAGE if PPC_64K_PAGES
+ select ARCH_SUPPORTS_NUMA_BALANCING
config PPC_BOOK3E_64
bool "Embedded processors"
--
1.8.3.2
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^ permalink raw reply related [flat|nested] 16+ messages in thread