[PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
To enable the do_numa_page(), we should not fix _PAGE_NUMA in
hash_page(), so bail out for the case of pte_numa().
Signed-off-by: Liu Ping Fan
---
arch/powerpc/mm/hash_utils_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index fb176e9..9bf1195 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1033,7 +1033,7 @@ int hash_page(unsigned long ea, unsigned long access,
unsigned long trap)
/* Get PTE and page size from page tables */
ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
- if (ptep == NULL || !pte_present(*ptep)) {
+ if (ptep == NULL || !pte_present(*ptep) || pte_numa(*ptep)) {
DBG_LOW(" no PTE !\n");
rc = 1;
goto bail;
--
1.8.1.4
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Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
Liu Ping Fan writes:
> To enable the do_numa_page(), we should not fix _PAGE_NUMA in
> hash_page(), so bail out for the case of pte_numa().
>
> Signed-off-by: Liu Ping Fan
> ---
> arch/powerpc/mm/hash_utils_64.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
> index fb176e9..9bf1195 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -1033,7 +1033,7 @@ int hash_page(unsigned long ea, unsigned long access,
> unsigned long trap)
>
> /* Get PTE and page size from page tables */
> ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
> - if (ptep == NULL || !pte_present(*ptep)) {
> + if (ptep == NULL || !pte_present(*ptep) || pte_numa(*ptep)) {
> DBG_LOW(" no PTE !\n");
> rc = 1;
> goto bail;
why ? , All the hash routines do check for _PAGE_PRESENT via access
variable.
-aneesh
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Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
On Thu, 2013-12-05 at 16:23 +0530, Aneesh Kumar K.V wrote: > Liu Ping Fan writes: > > > To enable the do_numa_page(), we should not fix _PAGE_NUMA in > > hash_page(), so bail out for the case of pte_numa(). For some reason I don't have 2/3 and 3/3 in my mbox (though I do have them on patchwork) so I'll reply to this one. Overall, your statement that this is a faster path needs to be backed up with numbers. The code is complicated enough as it-is, such additional mess in the low level hashing code requires a good justification, and also a demonstration that it doesn't add overhead to the normal hash path. Cheers, Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
On Mon, Dec 9, 2013 at 8:31 AM, Benjamin Herrenschmidt wrote: > On Thu, 2013-12-05 at 16:23 +0530, Aneesh Kumar K.V wrote: >> Liu Ping Fan writes: >> >> > To enable the do_numa_page(), we should not fix _PAGE_NUMA in >> > hash_page(), so bail out for the case of pte_numa(). > > For some reason I don't have 2/3 and 3/3 in my mbox (though I do have > them on patchwork) so I'll reply to this one. > > Overall, your statement that this is a faster path needs to be backed up > with numbers. > > The code is complicated enough as it-is, such additional mess in the low > level hashing code requires a good justification, and also a > demonstration that it doesn't add overhead to the normal hash path. > For the test, is it ok to have an user application to copy page where all page are PG_mlocked? Thanks and regards, Pingfan ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
On Mon, 2013-12-09 at 14:17 +0800, Liu ping fan wrote: > On Mon, Dec 9, 2013 at 8:31 AM, Benjamin Herrenschmidt > wrote: > > On Thu, 2013-12-05 at 16:23 +0530, Aneesh Kumar K.V wrote: > >> Liu Ping Fan writes: > >> > >> > To enable the do_numa_page(), we should not fix _PAGE_NUMA in > >> > hash_page(), so bail out for the case of pte_numa(). > > > > For some reason I don't have 2/3 and 3/3 in my mbox (though I do have > > them on patchwork) so I'll reply to this one. > > > > Overall, your statement that this is a faster path needs to be backed up > > with numbers. > > > > The code is complicated enough as it-is, such additional mess in the low > > level hashing code requires a good justification, and also a > > demonstration that it doesn't add overhead to the normal hash path. > > > For the test, is it ok to have an user application to copy page where > all page are PG_mlocked? If that specific scenario is relevant in practice, then yes, though also demonstrate the lack of regression with some more normal path such as a kernel compile. Cheers, Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
On Thu, Dec 5, 2013 at 6:53 PM, Aneesh Kumar K.V
wrote:
> Liu Ping Fan writes:
>
>> To enable the do_numa_page(), we should not fix _PAGE_NUMA in
>> hash_page(), so bail out for the case of pte_numa().
>>
>> Signed-off-by: Liu Ping Fan
>> ---
>> arch/powerpc/mm/hash_utils_64.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/mm/hash_utils_64.c
>> b/arch/powerpc/mm/hash_utils_64.c
>> index fb176e9..9bf1195 100644
>> --- a/arch/powerpc/mm/hash_utils_64.c
>> +++ b/arch/powerpc/mm/hash_utils_64.c
>> @@ -1033,7 +1033,7 @@ int hash_page(unsigned long ea, unsigned long access,
>> unsigned long trap)
>>
>> /* Get PTE and page size from page tables */
>> ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
>> - if (ptep == NULL || !pte_present(*ptep)) {
>> + if (ptep == NULL || !pte_present(*ptep) || pte_numa(*ptep)) {
>> DBG_LOW(" no PTE !\n");
>> rc = 1;
>> goto bail;
>
> why ? , All the hash routines do check for _PAGE_PRESENT via access
> variable.
>
Going through __hash_page_4K(4k on 4k HW), I do not find such check.
Am I wrong? Or I will send out a patch to fix that.
Thanks and regards,
Pingfan
> -aneesh
>
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Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
On Wed, 2013-12-11 at 16:50 +0800, Liu ping fan wrote: > > why ? , All the hash routines do check for _PAGE_PRESENT via access > > variable. > > > Going through __hash_page_4K(4k on 4k HW), I do not find such check. > Am I wrong? Or I will send out a patch to fix that. We pass a bitmask of flags to check which are tested by doing an "andc" of the PTE on that mask and checking if anything is left... Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 1/3] powerpc: mm: make _PAGE_NUMA take effect
On Wed, Dec 11, 2013 at 5:50 PM, Benjamin Herrenschmidt wrote: > On Wed, 2013-12-11 at 16:50 +0800, Liu ping fan wrote: >> > why ? , All the hash routines do check for _PAGE_PRESENT via access >> > variable. >> > >> Going through __hash_page_4K(4k on 4k HW), I do not find such check. >> Am I wrong? Or I will send out a patch to fix that. > > We pass a bitmask of flags to check which are tested by doing an "andc" > of the PTE on that mask and checking if anything is left... > Oh, see it, thank you very much Regards, Pingfan ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
