* Byungchul Park <byungchul.p...@lge.com> wrote:
> On Mon, Jul 04, 2016 at 07:27:54PM +0900, Byungchul Park wrote:
> > I suggested this patch on https://lkml.org/lkml/2016/6/20/22. However,
> > I want to proceed saperately since it's somewhat independent from each
> > other. Frankly speaking, I want this patchset to be accepted at first so
> > that the crossfeature can use this optimized save_stack_trace_norm()
> > which makes crossrelease work smoothly.
>
> What do you think about this way to improve it?
I like both of your improvements, the speed up is impressive:
[ 2.327597] save_stack_trace() takes 87114 ns
...
[ 2.781694] save_stack_trace() takes 20044 ns
...
[ 3.103264] save_stack_trace takes 3821 (sched_lock)
Could you please also measure call graph recording (perf record -g), how much
faster does it get with your patches and what are our remaining performance hot
spots?
Could you please merge your patches to the latest -tip tree, because this
commit I
merged earlier today:
81c2949f7fdc x86/dumpstack: Add show_stack_regs() and use it
conflicts with your patches. (I'll push this commit out later today.)
Also, could you please rename the _norm names to _fast or so, to signal that
this
is a faster but less reliable method to get a stack dump? Nobody knows what
'_norm' means, but '_fast' is pretty self-explanatory.
Thanks,
Ingo
