On Fri, Jul 08, 2016 at 12:08:19PM +0200, Ingo Molnar wrote: > > * 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?
Of course, I will. > > Could you please merge your patches to the latest -tip tree, because this > commit I > merged earlier today: Sure. > > 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. It would be better. Thank you, Byungchul > > Thanks, > > Ingo
