From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.thompson@linaro.org (Daniel Thompson) Date: Fri, 7 Apr 2017 18:09:39 +0100 Subject: [PATCH v1] arm64: Add support for on-demand backtrace of other CPUs In-Reply-To: <20170407170203.GC20645@e104818-lin.cambridge.arm.com> References: <1489735663-2091-1-git-send-email-andr2000@gmail.com> <1489735663-2091-2-git-send-email-andr2000@gmail.com> <20170407170203.GC20645@e104818-lin.cambridge.arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/04/17 18:02, Catalin Marinas wrote: > On Fri, Mar 17, 2017 at 09:27:43AM +0200, Oleksandr Andrushchenko wrote: >> From: Daniel Thompson >> >> Currently arm64 has no implementation of arch_trigger_cpumask_backtrace. >> The patch provides one using library code recently added by Russell King >> for for the majority of the implementation. Currently this is realized >> using regular irqs but could, in the future, be implemented using >> NMI-like mechanisms. >> >> Note: There is a small (and nasty) change to the generic code to ensure >> good stack traces. The generic code currently assumes that >> show_regs() will include a stack trace but arch/arm64 does not do >> this so we must add extra code here. Ideas on a better approach >> here would be very welcome (is there any appetite to change arm64 >> show_regs() or should we just tease out the dump code into a >> callback > > Please see this discussion here: > > http://lkml.kernel.org/r/20170323150357.GH9287 at leverpostej > > I'm not a ware of a follow up but if we change the arm64 show_regs() to > dump the stack, we no longer need the generic code hunk in your patch. Great. That hack did always irk me! I'll tidy it up the next time I push out the PMR interrupt masking patch set. Is there any interest in taking the patch before that. I don't mind separating it out... I'm just not sure how useful it is.