Re: [RFC 0/6] x86: prefetch_page() vDSO call

Nadav Amit
2021-02-25T09:37:25Z

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> On Feb 25, 2021, at 12:52 AM, Nadav Amit <nadav.amit@gmail.com> wrote:
>
>
>
>> On Feb 25, 2021, at 12:40 AM, Peter Zijlstra <peterz@infradead.org> wrote:
>>
>> On Wed, Feb 24, 2021 at 11:29:04PM -0800, Nadav Amit wrote:
>>> From: Nadav Amit <namit@vmware.com>
>>>
>>> Just as applications can use prefetch instructions to overlap
>>> computations and memory accesses, applications may want to overlap the
>>> page-faults and compute or overlap the I/O accesses that are required
>>> for page-faults of different pages.
[
[ snip ]

>> Interesting, but given we've been removing explicit prefetch from some
>> parts of the kernel how useful is this in actual use? I'm thinking there
>> should at least be a real user and performance numbers with this before
>> merging.
>
> Can you give me a reference to the “removing explicit prefetch from some
> parts of the kernel”?

Oh. I get it - you mean we remove we remove the use of explicit memory
prefetch from the kernel code. Well, I don’t think it is really related,
but yes, performance numbers are needed.

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