Received-SPF: pass (google.com: domain of linux-kernel+bounces-67900-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Precedence: bulk
MIME-Version: 1.0
References: <20240214225741.403783-1-souravpanda@google.com>
 <20240214225741.403783-2-souravpanda@google.com> <20240215161441.c8a2350a61f6929c0dbe9e7b@linux-foundation.org>
In-Reply-To: <20240215161441.c8a2350a61f6929c0dbe9e7b@linux-foundation.org>
From: Suren Baghdasaryan <surenb@google.com>
Date: Thu, 15 Feb 2024 16:39:50 -0800
Message-ID: <CAJuCfpHF=yxV9+=pUo+5DwSjvF=r2y7A9_8LHsUGUSoP7EUNXA@mail.gmail.com>
Subject: Re: [PATCH v8 1/1] mm: report per-page metadata information
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Sourav Panda <souravpanda@google.com>, corbet@lwn.net, gregkh@linuxfoundation.org, 
	rafael@kernel.org, mike.kravetz@oracle.com, muchun.song@linux.dev, 
	rppt@kernel.org, david@redhat.com, rdunlap@infradead.org, 
	chenlinxuan@uniontech.com, yang.yang29@zte.com.cn, tomas.mudrunka@gmail.com, 
	bhelgaas@google.com, ivan@cloudflare.com, pasha.tatashin@soleen.com, 
	yosryahmed@google.com, hannes@cmpxchg.org, shakeelb@google.com, 
	kirill.shutemov@linux.intel.com, wangkefeng.wang@huawei.com, 
	adobriyan@gmail.com, vbabka@suse.cz, Liam.Howlett@oracle.com, 
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, 
	linux-doc@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org, 
	weixugc@google.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Thu, Feb 15, 2024 at 4:14=E2=80=AFPM Andrew Morton <akpm@linux-foundatio=
n.org> wrote:
>
> On Wed, 14 Feb 2024 14:57:40 -0800 Sourav Panda <souravpanda@google.com> =
wrote:
>
> > Adds two new per-node fields, namely nr_memmap and nr_memmap_boot,
> > to /sys/devices/system/node/nodeN/vmstat and a global Memmap field
> > to /proc/meminfo. This information can be used by users to see how
> > much memory is being used by per-page metadata, which can vary
> > depending on build configuration, machine architecture, and system
> > use.
>
> Would this information be available by the proposed memory
> allocation profiling?

Well, not without jumping through the hoops. You would need to find
the places in the source code where all this matadata is allocated and
find the appropriate records inside /proc/allocinfo file.

>
> https://lkml.kernel.org/r/20240212213922.783301-1-surenb@google.com