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Re: [PATCH RESEND] kprobe: Use percpu counter to collect nhit statistics

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* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Thu, 4 Feb 2016 10:24:12 +0000
> 平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com> wrote:
> 
> > From: Martin KaFai Lau [mailto:kafai@fb.com]
> > >
> > >When doing ebpf+kprobe on some hot TCP functions (e.g.
> > >tcp_rcv_established), the kprobe_dispatcher shows up in 'perf report'.
> > >
> > >In kprobe_dispatcher(), there is a lot of cache bouncing
> > >in 'tk->nhit++'.  'tk->nhit' and 'tk->tp.flags' also share
> > >the same cacheline.
> > >  
> > 
> > Ingo, could you consider to merge this?
> > 
> 
> Ingo, you can also add my
> 
>  Acked-by: Steven Rostedt <rostedt@goodmis.org>

Yeah, nice optimization, picked it up - thanks guys!

	Ingo

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[PATCH RESEND] kprobe: Use percpu counter to collect nhit statistics Martin KaFai Lau <kafai@fb.com> - 2016-02-03 21:30 +0100
  RE: [PATCH RESEND] kprobe: Use percpu counter to collect nhit  statistics 平松雅巳 / HIRAMATU，MASAMI   <masami.hiramatsu.pt@hitachi.com> - 2016-02-04 11:30 +0100
    Re: [PATCH RESEND] kprobe: Use percpu counter to collect nhit  statistics Steven Rostedt <rostedt@goodmis.org> - 2016-02-04 14:30 +0100
      Re: [PATCH RESEND] kprobe: Use percpu counter to collect nhit  statistics Ingo Molnar <mingo@kernel.org> - 2016-02-09 11:10 +0100
  [tip:perf/core] kprobes:   Optimize hot path by using percpu counter to collect 'nhit' statistics tip-bot for Martin KaFai Lau <tipbot@zytor.com> - 2016-02-09 13:30 +0100

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