From: Keir Fraser <keir.xen@gmail.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>,
Xen-devel <xen-devel@lists.xen.org>
Cc: Tim Deegan <tim@xen.org>, Jan Beulich <jbeulich@suse.com>
Subject: Re: [PATCH 2/2] xen/conring: Write to console ring even if console lock is busted.
Date: Tue, 06 Aug 2013 15:44:07 +0100 [thread overview]
Message-ID: <CE26CA47.2FFEF%keir.xen@gmail.com> (raw)
In-Reply-To: <1375280572-15203-3-git-send-email-andrew.cooper3@citrix.com>
On 31/07/2013 15:22, "Andrew Cooper" <andrew.cooper3@citrix.com> wrote:
> console_lock_busted gets set when an NMI/MCE/Double Fault handler decides to
> bring Xen down in an emergency. conring_puts() cannot block and does
> not have problematic interactions with the console_lock.
>
> Therefore, choosing to not put the string into the console ring simply means
> that the kexec environment cant find any panic() message caused by an IST
> interrupt, which is unhelpful for debugging purposes.
>
> In the case that two pcpus fight with console_force_unlock(), having slightly
> garbled strings in the console ring is far more useful than having nothing at
> all.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: Keir Fraser <keir@xen.org>
> CC: Jan Beulich <jbeulich@suse.com>
> CC: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
next prev parent reply other threads:[~2013-08-06 14:44 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-31 14:22 xen/conring: Improvements Andrew Cooper
2013-07-31 14:22 ` [PATCH 1/2] xen/conring: Clean up writing to the console ring Andrew Cooper
2013-07-31 18:12 ` Matt Wilson
2013-08-06 14:43 ` Keir Fraser
2013-07-31 14:22 ` [PATCH 2/2] xen/conring: Write to console ring even if console lock is busted Andrew Cooper
2013-07-31 18:15 ` Matt Wilson
2013-08-06 14:44 ` Keir Fraser [this message]
2013-08-06 14:07 ` xen/conring: Improvements Andrew Cooper
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=CE26CA47.2FFEF%keir.xen@gmail.com \
--to=keir.xen@gmail.com \
--cc=andrew.cooper3@citrix.com \
--cc=jbeulich@suse.com \
--cc=tim@xen.org \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.