Re: [RFC PATCH V1 01/33] powerpc/mm: add _PAGE_HASHPTE similar to 4K hash

2016-01-12 Thread Aneesh Kumar K.V 
Balbir Singh  writes:

> On Tue, 12 Jan 2016 12:45:36 +0530
> "Aneesh Kumar K.V"  wrote:
>
>> Not really needed. But this brings it back to as it was before
>> 
>
> Could you expand on not really needed. Could the changelog describe how
> the bits will be used in the follow on patches.
>

What confused me in the beginning was difference between 4k and 64k
page size. I was trying to find out whether we miss a hpte flush in any
scenario because of this. ie, a pte update on a linux pte, for which we
are doing a parallel hash pte insert. After looking at it closer my
understanding is this won't happen because pte update also look at
_PAGE_BUSY and we will wait for hash pte insert to finish before going
ahead with the pte update. But to avoid further confusion I was wondering
whether we should keep this closer to what we have with __hash_page_4k.
Hence the statement "Not really needed".

-aneesh

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Re: [RFC PATCH V1 01/33] powerpc/mm: add _PAGE_HASHPTE similar to 4K hash

2016-01-12 Thread Balbir Singh 
On Tue, 12 Jan 2016 12:45:36 +0530
"Aneesh Kumar K.V"  wrote:

> Not really needed. But this brings it back to as it was before
> 

Could you expand on not really needed. Could the changelog describe how
the bits will be used in the follow on patches.

Balbir
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[RFC PATCH V1 01/33] powerpc/mm: add _PAGE_HASHPTE similar to 4K hash

2016-01-11 Thread Aneesh Kumar K.V 
Not really needed. But this brings it back to as it was before

Check this
41743a4e34f0777f51c1cf0675b91508ba143050

Signed-off-by: Aneesh Kumar K.V 
---
 arch/powerpc/mm/hash64_64k.c | 4 ++--
 arch/powerpc/mm/hugepage-hash64.c| 2 +-
 arch/powerpc/mm/hugetlbpage-hash64.c | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
index 0762c1e08c88..3c417f9099f9 100644
--- a/arch/powerpc/mm/hash64_64k.c
+++ b/arch/powerpc/mm/hash64_64k.c
@@ -76,7 +76,7 @@ int __hash_page_4K(unsigned long ea, unsigned long access, 
unsigned long vsid,
 * a write access. Since this is 4K insert of 64K page size
 * also add _PAGE_COMBO
 */
-   new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO;
+   new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO | 
_PAGE_HASHPTE;
if (access & _PAGE_RW)
new_pte |= _PAGE_DIRTY;
} while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
@@ -246,7 +246,7 @@ int __hash_page_64K(unsigned long ea, unsigned long access,
 * a write access. Since this is 4K insert of 64K page size
 * also add _PAGE_COMBO
 */
-   new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
+   new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE;
if (access & _PAGE_RW)
new_pte |= _PAGE_DIRTY;
} while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
diff --git a/arch/powerpc/mm/hugepage-hash64.c 
b/arch/powerpc/mm/hugepage-hash64.c
index 49b152b0f926..3c4bd4c0ade9 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -46,7 +46,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, 
unsigned long vsid,
 * Try to lock the PTE, add ACCESSED and DIRTY if it was
 * a write access
 */
-   new_pmd = old_pmd | _PAGE_BUSY | _PAGE_ACCESSED;
+   new_pmd = old_pmd | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE;
if (access & _PAGE_RW)
new_pmd |= _PAGE_DIRTY;
} while (old_pmd != __cmpxchg_u64((unsigned long *)pmdp,
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c 
b/arch/powerpc/mm/hugetlbpage-hash64.c
index e2138c7ae70f..9c224b012d62 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -54,7 +54,7 @@ int __hash_page_huge(unsigned long ea, unsigned long access, 
unsigned long vsid,
return 1;
/* Try to lock the PTE, add ACCESSED and DIRTY if it was
 * a write access */
-   new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
+   new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE;
if (access & _PAGE_RW)
new_pte |= _PAGE_DIRTY;
} while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
-- 
2.5.0

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