Re: [PATCH] mm: Add new vma flag VM_LOCAL_CPU

From: Boaz Harrosh
Date: Tue May 15 2018 - 13:39:51 EST

On 15/05/18 17:17, Peter Zijlstra wrote:
>> So I would love some mm guy to explain where are those bits collected?
> Depends on the architecture, some architectures only ever set bits,
> some, like x86, clear bits again. You want to look at switch_mm().
> Basically x86 clears the bit again when we switch away from the mm and
> have/will invalidate TLBs for it in doing so.

Ha, OK I am starting to get a picture.

>> Which brings me to another question. How can I find from
>> within a thread Say at the file_operations->mmap() call that the thread
>> is indeed core-pinned. What mm_cpumask should I inspect?
> is_percpu_thread().

Right thank you a lot Peter. this helps.

> .