From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser 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 Message-ID: References: <1375280572-15203-3-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1375280572-15203-3-git-send-email-andrew.cooper3@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper , Xen-devel Cc: Tim Deegan , Jan Beulich List-Id: xen-devel@lists.xenproject.org On 31/07/2013 15:22, "Andrew Cooper" 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 > CC: Keir Fraser > CC: Jan Beulich > CC: Tim Deegan Acked-by: Keir Fraser