* Re: [PATCH V5 16/17] mm: Let arch choose the initial value of task size
2017-03-22 3:37 ` [PATCH V5 16/17] mm: Let arch choose the initial value of task size Aneesh Kumar K.V
@ 2017-03-28 11:17 ` Michael Ellerman
2017-03-28 15:22 ` Aneesh Kumar K.V
2017-03-29 9:20 ` Anshuman Khandual
2017-03-30 3:03 ` Anshuman Khandual
2 siblings, 1 reply; 5+ messages in thread
From: Michael Ellerman @ 2017-03-28 11:17 UTC (permalink / raw)
To: Aneesh Kumar K.V, benh, paulus
Cc: linuxppc-dev, Kirill A . Shutemov, linux-mm, Andrew Morton
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:
> As we start supporting larger address space (>128TB), we want to give
> architecture a control on max task size of an application which is different
> from the TASK_SIZE. For ex: ppc64 needs to track the base page size of a segment
> and it is copied from mm_context_t to PACA on each context switch. If we know that
> application has not used an address range above 128TB we only need to copy
> details about 128TB range to PACA. This will help in improving context switch
> performance by avoiding larger copy operation.
>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: linux-mm@kvack.org
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> fs/exec.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
I'll need an ACK at least on this from someone in mm land.
I assume there's no way I can merge patch 17 without this?
> diff --git a/fs/exec.c b/fs/exec.c
> index 65145a3df065..5550a56d03c3 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1308,6 +1308,14 @@ void would_dump(struct linux_binprm *bprm, struct file *file)
> }
> EXPORT_SYMBOL(would_dump);
>
> +#ifndef arch_init_task_size
> +static inline void arch_init_task_size(void)
> +{
> + current->mm->task_size = TASK_SIZE;
> +}
> +#define arch_init_task_size arch_init_task_size
I don't think you need to do the #define in the fallback case, it's
just extra noise.
> +#endif
> +
> void setup_new_exec(struct linux_binprm * bprm)
> {
> arch_pick_mmap_layout(current->mm);
cheers
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH V5 16/17] mm: Let arch choose the initial value of task size
2017-03-28 11:17 ` Michael Ellerman
@ 2017-03-28 15:22 ` Aneesh Kumar K.V
0 siblings, 0 replies; 5+ messages in thread
From: Aneesh Kumar K.V @ 2017-03-28 15:22 UTC (permalink / raw)
To: Michael Ellerman, benh, paulus
Cc: linuxppc-dev, Kirill A . Shutemov, linux-mm, Andrew Morton
On Tuesday 28 March 2017 04:47 PM, Michael Ellerman wrote:
> "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:
>
>> As we start supporting larger address space (>128TB), we want to give
>> architecture a control on max task size of an application which is different
>> from the TASK_SIZE. For ex: ppc64 needs to track the base page size of a segment
>> and it is copied from mm_context_t to PACA on each context switch. If we know that
>> application has not used an address range above 128TB we only need to copy
>> details about 128TB range to PACA. This will help in improving context switch
>> performance by avoiding larger copy operation.
>>
>> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>> Cc: linux-mm@kvack.org
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>> fs/exec.c | 10 +++++++++-
>> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> I'll need an ACK at least on this from someone in mm land.
>
> I assume there's no way I can merge patch 17 without this?
That is correct.
I didn't add linux-mm to cc for rest of the patches. They are all ppc64
specific and can be found at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2017-March/155726.html
-aneesh
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH V5 16/17] mm: Let arch choose the initial value of task size
2017-03-22 3:37 ` [PATCH V5 16/17] mm: Let arch choose the initial value of task size Aneesh Kumar K.V
2017-03-28 11:17 ` Michael Ellerman
@ 2017-03-29 9:20 ` Anshuman Khandual
2017-03-30 3:03 ` Anshuman Khandual
2 siblings, 0 replies; 5+ messages in thread
From: Anshuman Khandual @ 2017-03-29 9:20 UTC (permalink / raw)
To: Aneesh Kumar K.V, benh, paulus, mpe
Cc: linuxppc-dev, Kirill A . Shutemov, linux-mm, Andrew Morton
[-- Attachment #1: Type: text/plain, Size: 1505 bytes --]
On Wednesday 22 March 2017 09:07 AM, Aneesh Kumar K.V wrote:
> As we start supporting larger address space (>128TB), we want to give
> architecture a control on max task size of an application which is different
> from the TASK_SIZE. For ex: ppc64 needs to track the base page size of a segment
> and it is copied from mm_context_t to PACA on each context switch. If we know that
> application has not used an address range above 128TB we only need to copy
> details about 128TB range to PACA. This will help in improving context switch
> performance by avoiding larger copy operation.
>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: linux-mm@kvack.org
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> fs/exec.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 65145a3df065..5550a56d03c3 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1308,6 +1308,14 @@ void would_dump(struct linux_binprm *bprm, struct file *file)
> }
> EXPORT_SYMBOL(would_dump);
>
> +#ifndef arch_init_task_size
> +static inline void arch_init_task_size(void)
> +{
> + current->mm->task_size = TASK_SIZE;
> +}
> +#define arch_init_task_size arch_init_task_size
> +#endif
Why not a proper CONFIG_ARCH_DEFINED_TASK_SIZE kind of option for this ?
Also
are there no assumptions about task current->mm->size being TASK_SIZE in
other
places which might get broken ?
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH V5 16/17] mm: Let arch choose the initial value of task size
2017-03-22 3:37 ` [PATCH V5 16/17] mm: Let arch choose the initial value of task size Aneesh Kumar K.V
2017-03-28 11:17 ` Michael Ellerman
2017-03-29 9:20 ` Anshuman Khandual
@ 2017-03-30 3:03 ` Anshuman Khandual
2 siblings, 0 replies; 5+ messages in thread
From: Anshuman Khandual @ 2017-03-30 3:03 UTC (permalink / raw)
To: Aneesh Kumar K.V, benh, paulus, mpe
Cc: linuxppc-dev, Kirill A . Shutemov, linux-mm, Andrew Morton
On 03/22/2017 09:07 AM, Aneesh Kumar K.V wrote:
> As we start supporting larger address space (>128TB), we want to give
> architecture a control on max task size of an application which is different
> from the TASK_SIZE. For ex: ppc64 needs to track the base page size of a segment
> and it is copied from mm_context_t to PACA on each context switch. If we know that
> application has not used an address range above 128TB we only need to copy
> details about 128TB range to PACA. This will help in improving context switch
> performance by avoiding larger copy operation.
>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: linux-mm@kvack.org
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> fs/exec.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 65145a3df065..5550a56d03c3 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1308,6 +1308,14 @@ void would_dump(struct linux_binprm *bprm, struct file *file)
> }
> EXPORT_SYMBOL(would_dump);
>
> +#ifndef arch_init_task_size
> +static inline void arch_init_task_size(void)
> +{
> + current->mm->task_size = TASK_SIZE;
> +}
> +#define arch_init_task_size arch_init_task_size
> +#endif
Why not a proper CONFIG_ARCH_DEFINED_TASK_SIZE kind of option for
this ? Also are there no assumptions about task current->mm->size
being TASK_SIZE in other places which might get broken ?
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^ permalink raw reply [flat|nested] 5+ messages in thread