Re: [PATCH v2 0/4] Introduce and use absolute_pointer macro

From: Matt Turner <mattst88@gmail.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ulrich Teichert <krypton@ulrich-teichert.org>,
	Michael Cree <mcree@orcon.net.nz>,
	Guenter Roeck <linux@roeck-us.net>,
	Richard Henderson <rth@twiddle.net>,
	Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
	"James E . J . Bottomley" <James.Bottomley@hansenpartnership.com>,
	Helge Deller <deller@gmx.de>,
	"David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	alpha <linux-alpha@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-parisc <linux-parisc@vger.kernel.org>,
	Netdev <netdev@vger.kernel.org>,
	Sparse Mailing-list <linux-sparse@vger.kernel.org>
Subject: Re: [PATCH v2 0/4] Introduce and use absolute_pointer macro
Date: Mon, 20 Sep 2021 11:59:05 -0700	[thread overview]
Message-ID: <CAEdQ38HeUPDyiZhhriHqdA+Qeyrb3M=FoKWKgs0dZaEjbcpVUQ@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wibRWoy4-ZkSVXUoGsUw5wKovPvRhS7r6VM+_GeBYZw1A@mail.gmail.com>

On Mon, Sep 20, 2021 at 11:46 AM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> On Mon, Sep 20, 2021 at 11:26 AM Ulrich Teichert
> <krypton@ulrich-teichert.org> wrote:
> >
> > The main trouble is that my system has only 64MB of memory and the smallest
> > kernel image with all drivers I need was about 105MB big.
>
> Are you sure you aren't looking at some debug image?
>
> I just tried building something based on your Jensen config (lots of
> new questions, you sent your old config from 4.18.0-rc5 time), and I
> get
>
>   [torvalds@ryzen linux]$ ll -h arch/alpha/boot/vmlinux*
>   -rwxr-xr-x. 1 torvalds torvalds 5.4M Sep 20 11:32 arch/alpha/boot/vmlinux
>   -rw-r--r--. 1 torvalds torvalds 2.3M Sep 20 11:32 arch/alpha/boot/vmlinux.gz
>
> so yeah, it's not exactly tiny, but at 5.4MB it's certainly not 105MB.
>
> The "vmlinux" file itself is huge, but that's due to CONFIG_DEBUG_INFO=y.
>
> You can easily disable DEBUG_INFO entirely (or at least do
> DEBUG_INFO_REDUCED), and get much smaller files.
>
> With the attached config, the vmlinux file is just 7MB (but the actual
> one you boot is that same 5.4M file because it's been stripped).
>
> NOTE! The attached config is basically just the one you sent me, with
> "make defconfig" done and DEBUG_INFO removed. It might have drivers
> missing, or extraneous code that you don't need because of all the
> changes in config variables since that very old one.
>
> It would be very interesting to hear whether this all still boots. I
> do think people still occasionally boot-test some other alpha
> configurations, but maybe not.

I test on a couple of alpha configurations with some regularity:
Marvel (AlphaServer ES47) and Nautilus (UP1500). I have more systems I
could test but I'd need to get a lot more organized to make space.

In the decade plus I've been around Linux on alpha I've don't actually
recall hearing of anyone using Linux on a Jensen system before :)