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.
