Messages in this thread | | | Date | Tue, 22 Nov 2016 11:05:50 -0800 | From | Andi Kleen <> | Subject | Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! |
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On Tue, Nov 22, 2016 at 09:39:45AM -0500, Steven Rostedt wrote: > On Mon, 21 Nov 2016 10:37:00 -0800 > Andi Kleen <andi@firstfloor.org> wrote: > > > > Here is it again untruncated: > > > > http://halobates.de/tracepoint-trace > > BTW, what tool did you use to generate this?
perf and Intel PT, with the disassembler patches added and udis86 installed:
https://git.kernel.org/cgit/linux/kernel/git/ak/linux-misc.git/log/?h=perf/disassembler-2 http://udis86.sourceforge.net/
You need a CPU that supports PT, like Broadwell, Skylake, Goldmont.
# enable trace point perf record -e intel_pt// -a sleep X perf script --itrace=i0ns --ns -F cpu,ip,time,asm,sym
On Skylake can also get more accurate timing by enabling cycle timing (at the cost of some overhead)
perf record -e intel_pt/cyc=1,cyc_thresh=1/ -a ...
The earlier trace didn't have that enabled.
-Andi
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