From mboxrd@z Thu Jan 1 00:00:00 1970 From: atomlin@redhat.com (Aaron Tomlin) Date: Thu, 14 Apr 2016 16:19:33 +0100 Subject: [PATCH v5 2/4] nmi_backtrace: do a local dump_stack() instead of a self-NMI In-Reply-To: <1459877208-15119-3-git-send-email-cmetcalf@mellanox.com> References: <1459877208-15119-1-git-send-email-cmetcalf@mellanox.com> <1459877208-15119-3-git-send-email-cmetcalf@mellanox.com> Message-ID: <20160414151933.GF20425@atomlin.usersys.redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue 2016-04-05 13:26 -0400, Chris Metcalf wrote: > Currently on arm there is code that checks whether it should call > dump_stack() explicitly, to avoid trying to raise an NMI when the > current context is not preemptible by the backtrace IPI. Similarly, > the forthcoming arch/tile support uses an IPI mechanism that does > not support generating an NMI to self. > > Accordingly, move the code that guards this case into the generic > mechanism, and invoke it unconditionally whenever we want a > backtrace of the current cpu. It seems plausible that in all cases, > dump_stack() will generate better information than generating a > stack from the NMI handler. The register state will be missing, > but that state is likely not particularly helpful in any case. > > Or, if we think it is helpful, we should be capturing and emitting > the current register state in all cases when regs == NULL is passed > to nmi_cpu_backtrace(). > > Signed-off-by: Chris Metcalf > --- > arch/arm/kernel/smp.c | 9 --------- > lib/nmi_backtrace.c | 9 +++++++++ > 2 files changed, 9 insertions(+), 9 deletions(-) Thanks Chris. Acked-by: Aaron Tomlin -- Aaron Tomlin