From: Peter Zijlstra <peterz@infradead.org>
To: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jiri Kosina <jkosina@suse.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/spinlocks: Avoid a deadlock when someone unlock a zapped ticked spinlock
Date: Thu, 22 Oct 2015 12:16:26 +0200 [thread overview]
Message-ID: <20151022101626.GN2508@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20151022093937.GA2599@pathway.suse.cz>
On Thu, Oct 22, 2015 at 11:39:38AM +0200, Petr Mladek wrote:
> Maybe, we could add support to use early console in case of Oops and
> panic. But we should not do this by default. It would help, especially
> when the problem is reproducible and we get stacked with the normal
> console.
What I typically do is route everything to 8250 early console and rip
out everything printk buffer nonsense.
That gets you a fairly reliable console, no locking, only vscnprintf()
and OUTB banging.
No printk() wanting to do wakeups and other such nonsense that doesn't
work.
I appreciate that might not be for everybody, but it also shouldn't be
this hard to get something reliable.
prev parent reply other threads:[~2015-10-22 10:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-21 9:18 Petr Mladek
2015-10-21 11:11 ` Peter Zijlstra
2015-10-22 9:39 ` Petr Mladek
2015-10-22 10:16 ` Peter Zijlstra [this message]
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