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From:   Yosry Ahmed <yosryahmed@google.com>
Date:   Mon, 13 Jun 2022 10:11:23 -0700
Message-ID: <CAJD7tkbUXb7qBm1GAMDr29DcsC90_bPzwffkdtAu_Na+inVzVg@mail.gmail.com>
Subject: Re: [PATCH v5 1/4] mm: add NR_SECONDARY_PAGETABLE to count secondary
 page table uses.
To:     "Huang, Shaoqin" <shaoqin.huang@intel.com>
Cc:     Tejun Heo <tj@kernel.org>, Johannes Weiner <hannes@cmpxchg.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        Oliver Upton <oupton@google.com>,
        Cgroups <cgroups@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        kvm@vger.kernel.org, Linux-MM <linux-mm@kvack.org>
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On Sun, Jun 12, 2022 at 8:18 PM Huang, Shaoqin <shaoqin.huang@intel.com> wrote:
>
>
>
> On 6/7/2022 6:20 AM, 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.
> >
> > This stat will be used by subsequent patches to count KVM mmu
> > memory usage.
> >
> > Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
> > ---
> >   Documentation/admin-guide/cgroup-v2.rst | 5 +++++
> >   Documentation/filesystems/proc.rst      | 4 ++++
> >   drivers/base/node.c                     | 2 ++
> >   fs/proc/meminfo.c                       | 2 ++
> >   include/linux/mmzone.h                  | 1 +
> >   mm/memcontrol.c                         | 1 +
> >   mm/page_alloc.c                         | 6 +++++-
> >   mm/vmstat.c                             | 1 +
> >   8 files changed, 21 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> > index 69d7a6983f781..307a284b99189 100644
> > --- a/Documentation/admin-guide/cgroup-v2.rst
> > +++ b/Documentation/admin-guide/cgroup-v2.rst
> > @@ -1312,6 +1312,11 @@ PAGE_SIZE multiple when read back.
> >         pagetables
> >                   Amount of memory allocated for page tables.
> >
> > +       sec_pagetables
> > +             Amount of memory allocated for secondary page tables,
> > +             this currently includes KVM mmu allocations on x86
> > +             and arm64.
> > +
> >         percpu (npn)
> >               Amount of memory used for storing per-cpu kernel
> >               data structures.
> > diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
> > index 061744c436d99..894d6317f3bdc 100644
> > --- a/Documentation/filesystems/proc.rst
> > +++ b/Documentation/filesystems/proc.rst
> > @@ -973,6 +973,7 @@ You may not have all of these fields.
> >       SReclaimable:   159856 kB
> >       SUnreclaim:     124508 kB
> >       PageTables:      24448 kB
> > +    SecPageTables:    0 kB
> >       NFS_Unstable:        0 kB
> >       Bounce:              0 kB
> >       WritebackTmp:        0 kB
> > @@ -1067,6 +1068,9 @@ SUnreclaim
> >   PageTables
> >                 amount of memory dedicated to the lowest level of page
> >                 tables.
> > +SecPageTables
> > +           amount of memory dedicated to secondary page tables, this
> > +           currently includes KVM mmu allocations on x86 and arm64.
>
> Just a notice. This patch in the latest 5.19.0-rc2+ have a conflict in
> Documentation/filesystems/proc.rst file. But that's not a problem.

Thanks for pointing this out. Let me know if a rebase and resend is necessary.

<snip>