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From:   Yosry Ahmed <yosryahmed@google.com>
Date:   Mon, 27 Jun 2022 09:23:55 -0700
Message-ID: <CAJD7tkaMYhG7_AQgn6fLGFVuSB4wDpY_GzcvSS99tSzTUKFkTw@mail.gmail.com>
Subject: Re: [PATCH v5 1/4] mm: add NR_SECONDARY_PAGETABLE to count secondary
 page table uses.
To:     Sean Christopherson <seanjc@google.com>
Cc:     Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Marc Zyngier <maz@kernel.org>,
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On Mon, Jun 27, 2022 at 9:07 AM Sean Christopherson <seanjc@google.com> 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@kernel.org

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