Re: [PATCH v5 1/4] mm: add NR_SECONDARY_PAGETABLE to count secondary page table uses.

From: Yosry Ahmed
Date: Mon Jun 27 2022 - 12:24:38 EST


On Mon, Jun 27, 2022 at 9:07 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Mon, Jun 06, 2022, Yosry Ahmed wrote:
> > Add NR_SECONDARY_PAGETABLE stat to count secondary page table uses, e.g.
> > KVM mmu. This provides more insights on the kernel memory used
> > by a workload.
>
> Please provide more justification for NR_SECONDARY_PAGETABLE in the changelog.
> Specially, answer the questions that were asked in the previous version:
>
> 1. Why not piggyback NR_PAGETABLE?
> 2. Why a "generic" NR_SECONDARY_PAGETABLE instead of NR_VIRT_PAGETABLE?
>
> It doesn't have to be super long, but provide enough info so that reviewers and
> future readers don't need to go spelunking to understand the motivation for the
> new counter type.

I added such justification in the cover letter, is it better to
include it here alternatively?
or do you think the description in the cover letter is lacking?

>
> And it's probably worth an explicit Link to Marc's question that prompted the long
> discussion in the previous version, that way if someone does want the gory details
> they have a link readily available.
>
> Link: https://lore.kernel.org/all/87ilqoi77b.wl-maz@xxxxxxxxxx

I will include the link in the next version.
Thanks!