Re: [PATCH v2 4/4] nmi_backtrace: generate one-line reports for idle cpus

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 4/4] nmi_backtrace: generate one-line reports for idle cpus
Date	2016-03-21 22:50 +0100
Message-ID	<rffS2-34o-9@gated-at.bofh.it> (permalink)
References	<rdLW2-35m-9@gated-at.bofh.it> <rdoG6-4jI-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed, Mar 16, 2016 at 01:02:13PM -0400, Chris Metcalf wrote:
> When doing an nmi backtrace of many cores, most of which are idle,
> the output is a little overwhelming and very uninformative.  Suppress
> messages for cpus that are idling when they are interrupted and just
> emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".

This is still 100+ lines on a modern system, but better than the many
many thousands it would otherwise generate.

> We do this by grouping all the cpuidle code together into a new
> .cpuidle.text section, and then checking the address of the
> interrupted PC to see if it lies within that section.
> 
> Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Please Cc Rafael on the next posting.

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

Re: [PATCH v2 4/4] nmi_backtrace: generate one-line reports for idle  cpus Peter Zijlstra <peterz@infradead.org> - 2016-03-21 22:50 +0100

csiph-web