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

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Message-ID: <20160204081957.3c31f719@gandalf.local.home>
Date:	Thu, 4 Feb 2016 08:19:57 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	平松雅巳 /
	 HIRAMATU，MASAMI 
	<masami.hiramatsu.pt@...achi.com>
Cc:	"'Martin KaFai Lau'" <kafai@...com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...hat.com>,
	Alexei Starovoitov <alexei.starovoitov@...il.com>,
	Josef Bacik <jbacik@...com>, Kernel Team <kernel-team@...com>
Subject: Re: [PATCH RESEND] kprobe: Use percpu counter to collect nhit
 statistics

On Thu, 4 Feb 2016 10:24:12 +0000
平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@...achi.com> wrote:

> From: Martin KaFai Lau [mailto:kafai@...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@...dmis.org>

-- Steve