From: David Vrabel <david.vrabel@citrix.com>
To: Warner Wang <warner.wang@hp.com>
Cc: keir@xen.org, jbeulich@suse.com, xen-devel@lists.xen.org
Subject: Re: [PATCH] x86: keep the crash kernel below 896 MiB
Date: Thu, 25 Apr 2013 12:01:17 +0100 [thread overview]
Message-ID: <51790CFD.4000707@citrix.com> (raw)
In-Reply-To: <1366880223-15439-1-git-send-email-warner.wang@hp.com>
On 25/04/13 09:57, Warner Wang wrote:
> When use the crashkernel=size parameter without specifying a "@xM"
> suffix, the crashkernel will be reserved at the highest suitable
> address of memory, this will make the kexec-tools fail to work.
> The current kexec-tools have a limitation that it can only work
> with crashkernel reserved under 896 MiB. we can increase this
> limit once kexec-tools are fixed.
> Linux kernel itself have this code for kexec-tools limitation,
> so I think Xen code should also have it.
I don't think we should limit Xen in this way for any particular tool.
It's trivial to specify a location in the crashkernel parameter to work
around this particular tool limitation.
I also think that this limitation may well be fixed as of kexec-tools
2.0.4. 64-bit kernels are now loaded above 4 GiB.
David
> Signed-off-by: Warner Wang <warner.wang@hp.com>
> ---
> xen/arch/x86/setup.c | 7 +++++++
> 1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> index 43301a5..ae4c947 100644
> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c
> @@ -943,6 +943,13 @@ void __init __start_xen(unsigned long mbi_p)
> }
> }
>
> + /*
> + * Keep the crash kernel below this limit. On 64 bits, kexec-tools
> + * currently limits us to 896 MiB; increase this limit once kexec-tools
> + * are fixed.
> + */
> + e = min_t(uint64_t, e, 896 << 20);
> +
> /* Don't overlap with modules. */
> e = consider_modules(s, e, PAGE_ALIGN(kexec_crash_area.size),
> mod, mbi->mods_count, -1);
prev parent reply other threads:[~2013-04-25 11:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-25 8:57 [PATCH] x86: keep the crash kernel below 896 MiB Warner Wang
2013-04-25 9:51 ` Jan Beulich
2013-04-25 10:48 ` Andrew Cooper
2013-04-25 11:01 ` David Vrabel [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=51790CFD.4000707@citrix.com \
--to=david.vrabel@citrix.com \
--cc=jbeulich@suse.com \
--cc=keir@xen.org \
--cc=warner.wang@hp.com \
--cc=xen-devel@lists.xen.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).