Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2 1/4] nmi_backtrace: add more trigger_*_cpu_backtrace() methods | From | Chris Metcalf <> | Date | Thu, 17 Mar 2016 18:41:42 -0400 |
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On 3/17/2016 6:38 PM, Peter Zijlstra wrote: > On Thu, Mar 17, 2016 at 06:31:44PM -0400, Chris Metcalf wrote: >> On 3/17/2016 3:36 PM, Peter Zijlstra wrote: >>> On Wed, Mar 16, 2016 at 01:02:10PM -0400, Chris Metcalf wrote: >>>> Currently you can only request a backtrace of either all cpus, or >>>> all cpus but yourself. It can also be helpful to request a remote >>>> backtrace of a single cpu, and since we want that, the logical >>>> extension is to support a cpumask as the underlying primitive. >>>> >>>> This change modifies the existing lib/nmi_backtrace.c code to take >>>> a cpumask as its basic primitive, and modifies the linux/nmi.h code >>>> to use either the old "all/all_but_self" arch methods, or the new >>>> "cpumask" method, depending on which is available. >>>> >>>> The existing clients of nmi_backtrace (arm and x86) are converted >>>> to using the new cpumask approach in this change. >>> So the past days I've been staring at RCU stall warns, and they can use >>> a little of this. Their remote stack unwinds are less than useful. >> Were you suggesting this as an improvement for a possible v3, or just a >> kind of implicit ack of the patch series? Thanks! > A suggestion more like. I've not actually looked at the 4th patch. > > I'll try and fold the patches into the runs I do tomorrow, I'm sure to > trigger lots of fail. Maybe I'll even do that RCU patch.
The build bot caught the fact that I missed arch/xtensa since it doesn't use LOCK_TEXT, so if you're testing on that (ok maybe unlikely) you can add this:
diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S index c417cbe4ec87..18a174c7fb87 100644 --- a/arch/xtensa/kernel/vmlinux.lds.S +++ b/arch/xtensa/kernel/vmlinux.lds.S @@ -93,6 +93,9 @@ SECTIONS VMLINUX_SYMBOL(__sched_text_start) = .; *(.sched.literal .sched.text) VMLINUX_SYMBOL(__sched_text_end) = .; + VMLINUX_SYMBOL(__cpuidle_text_start) = .; + *(.cpuidle.literal .cpuidle.text) + VMLINUX_SYMBOL(__cpuidle_text_end) = .; VMLINUX_SYMBOL(__lock_text_start) = .; *(.spinlock.literal .spinlock.text) VMLINUX_SYMBOL(__lock_text_end) = .;
-- Chris Metcalf, Mellanox Technologies http://www.mellanox.com
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