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Subject: Re: [PATCH v9 21/24] perf tools: Add support for the SPF perf event
To:     David Rientjes <rientjes@google.com>,
        Andi Kleen <ak@linux.intel.com>
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From:   Laurent Dufour <ldufour@linux.vnet.ibm.com>
Date:   Thu, 12 Apr 2018 15:44:36 +0200
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On 10/04/2018 08:47, David Rientjes wrote:
> On Mon, 26 Mar 2018, Andi Kleen wrote:
> 
>>> Aside: should there be a new spec_flt field for struct task_struct that 
>>> complements maj_flt and min_flt and be exported through /proc/pid/stat?
>>
>> No. task_struct is already too bloated. If you need per process tracking 
>> you can always get it through trace points.
>>
> 
> Hi Andi,
> 
> We have
> 
> 	count_vm_event(PGFAULT);
> 	count_memcg_event_mm(vma->vm_mm, PGFAULT);
> 
> in handle_mm_fault() but not counterpart for spf.  I think it would be 
> helpful to be able to determine how much faulting can be done 
> speculatively if there is no per-process tracking without tracing.

That sounds to be a good idea, I will create a separate patch a dedicated
speculative_pgfault counter as PGFAULT is.

Thanks,
Laurent.