Date: Mon, 11 Mar 2013 15:02:42 -0400
From: Vivek Goyal <vgoyal@redhat.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@elte.hu>, WANG Chao <chaowang@redhat.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86, kdump: Set crashkernel_low automatically
Message-ID: <20130311190242.GC12107@redhat.com>
References: <513D52BA.3070206@redhat.com>
 <1362977817-23297-1-git-send-email-yinghai@kernel.org>
 <20130311144853.GB8482@redhat.com>
 <20130311150256.GC8482@redhat.com>
 <CAE9FiQW1CHJ-j9aFgdtKEsgyZSTHTS1HzgMSGM8FnV7Ns3kUvw@mail.gmail.com>
 <20130311182655.GB12107@redhat.com>
 <513E2695.3080707@zytor.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <513E2695.3080707@zytor.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1534
Lines: 38

On Mon, Mar 11, 2013 at 11:46:45AM -0700, H. Peter Anvin wrote:
> On 03/11/2013 11:26 AM, Vivek Goyal wrote:
> >>
> > Hi Yinghai,
> > 
> > In mutt your patches are showing as attachment instead of inline. Mutt
> > thinks attachment is of type "application/octet-stream". Not sure if
> > this is configuration issue on my part or something is going on your
> > end.
> > 
> > I have few more concerns.
> > 
> > - Are we able to reserve 512MB memory now below 896MB. I remember so
> >   far it was broken.
> > 
> 
> What is the purpose of reserving that kind of memory below 896 MB?  If
> you have a 32-bit system, it will likely be useless since you are
> robbing the primary of most of lowmem, on a 64-bit system 896 MB is not
> a magic value in any way...?

Actually I am not sure where did 896MB magic value had come from for
x86_64 so far. I assumed that it was some kexec-tools limitation so
first trying 896MB will preserve working with old kexec-tools. If it
was some kernel limitation, then I agree it should not be required anymore.

I do remember that old pugatory had 2G limit. So may be we can first
try reserve with-in first 2G, then with-in first 4G and then above
4G. (Assuming 896M was not kexec-tools limitation and had something
to do with kernel/initramfs).

Thanks
Vivek
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/