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From: Pintu Agarwal <pintu.ping@gmail.com>
Date: Fri, 24 May 2024 23:03:26 +0530
Message-ID: <CAOuPNLhN16FcYyAj7i2S9P7wJr+Z1LTDOOOkDZUwwq1_ZMiv3A@mail.gmail.com>
Subject: Re: (2) [RESEND PATCH 00/10] memblock: introduce memsize showing
 reserved memory
To: Mike Rapoport <rppt@kernel.org>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>, "vbabka@suse.cz" <vbabka@suse.cz>, 
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, 
	"jaewon31.kim@gmail.com" <jaewon31.kim@gmail.com>, "tkjos@google.com" <tkjos@google.com>
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On Thu, 23 May 2024 at 20:06, Mike Rapoport <rppt@kernel.org> wrote:
>
> On Tue, May 21, 2024 at 07:17:53PM +0900, Jaewon Kim wrote:
> > >On Tue, May 21, 2024 at 11:53:29AM +0900, Jaewon Kim wrote:
> > >> >--------- Original Message ---------
> > >> >Sender : =EA=B9=80=EC=9E=AC=EC=9B=90 <jaewon31.kim@samsung.com>Syst=
em Performance Lab.(MX)/=EC=82=BC=EC=84=B1=EC=A0=84=EC=9E=90
> > >> >Date   : 2024-05-21 11:40 (GMT+9)
> > >> >Title  : [RESEND PATCH 00/10] memblock: introduce memsize showing r=
eserved memory
> > >> >?
> > >> >Some of memory regions can be reserved for a specific purpose. They=
 are
> > >> >usually defined through reserved-memory in device tree. If only siz=
e
> > >> >without address is specified in device tree, the address of the reg=
ion
> > >> >will be determined at boot time.
> > >> >
> > >> >We may find the address of the memory regions through booting log, =
but
> > >> >it does not show all. And it could be hard to catch the very beginn=
ing
> > >> >log. The memblock_dump_all shows all memblock status but it does no=
t
> > >> >show region name and its information is difficult to summarize.

Something similar, we have already proposed almost 10 years ago for membloc=
k.
That time I realised some of these reserved memory break-up becomes
useful and handy when we are gathering reserved memory stats on a
small embedded device where every bit of memory reserved is important
and being questioned.

You can get some information about Kernel reserved from dmesg | grep
-i Memory (including the kernel init, text, data) and the cma-reserved
as well. Here the cma-reserved was added by me.

You can also get these Kernel reserved size info from vmlinux.
size -t vmlinux