From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <bsingharora@gmail.com>
Received: from mail-pg0-x243.google.com (mail-pg0-x243.google.com
 [IPv6:2607:f8b0:400e:c05::243])
 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
 (No client certificate requested)
 by lists.ozlabs.org (Postfix) with ESMTPS id 3vzCMT1hk1zDqLK
 for <linuxppc-dev@lists.ozlabs.org>; Thu,  6 Apr 2017 16:23:33 +1000 (AEST)
Received: by mail-pg0-x243.google.com with SMTP id o123so6201753pga.1
 for <linuxppc-dev@lists.ozlabs.org>; Wed, 05 Apr 2017 23:23:33 -0700 (PDT)
Message-ID: <1491459805.12351.8.camel@gmail.com>
Subject: Re: [RFC] [PATCH] Trace TLBIE's
From: Balbir Singh <bsingharora@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>, Alistair Popple
 <alistair@popple.id.au>, linuxppc-dev@lists.ozlabs.org
Cc: linuxppc-dev <linuxppc-dev@ozlabs.org>, Paul Mackerras
 <paulus@samba.org>,  Nicholas Piggin <npiggin@gmail.com>
Date: Thu, 06 Apr 2017 16:23:25 +1000
In-Reply-To: <8760iiul7r.fsf@concordia.ellerman.id.au>
References: <3dcd0c76-46fd-cb7a-945d-4b5a679fa544@gmail.com>
 <87polmtscd.fsf@concordia.ellerman.id.au>
 <8a496713-bc00-6520-b715-481de507363e@gmail.com>
 <2637022.69IxkT9g0N@new-mexico> <8760iiul7r.fsf@concordia.ellerman.id.au>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
List-Id: Linux on PowerPC Developers Mail List <linuxppc-dev.lists.ozlabs.org>
List-Unsubscribe: <https://lists.ozlabs.org/options/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>
List-Archive: <http://lists.ozlabs.org/pipermail/linuxppc-dev/>
List-Post: <mailto:linuxppc-dev@lists.ozlabs.org>
List-Help: <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>
List-Subscribe: <https://lists.ozlabs.org/listinfo/linuxppc-dev>,
 <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>

On Thu, 2017-04-06 at 16:03 +1000, Michael Ellerman wrote:
> Alistair Popple <alistair@popple.id.au> writes:
> 
> > On Wed, 23 Nov 2016 10:40:36 PM Balbir Singh wrote:
> > > 
> > > > But overall I guess it's OK. We'd want to do a quick benchmark to make
> > > > sure it's not adding any overhead.
> > > 
> > > OK.. I'll try and find a benchmark and run it with traces disabled.
> > 
> > For what's it's worth I didn't notice any slow down running a NAMD
> > test with tracing disabled and ~400000 tlbie's in 34s. Turning tracing
> > on could have slowed things down ever so slightly, but I didn't notice
> > as it may have just been in the noise of the benchmark I was running
> > (I wasn't specifically looking at timing, hence the vagueness of the
> > remarks).
> > 
> > Otherwise the patch worked and would be useful - I have already had to
> > setup tlbie counting/tracing several times in the last 12 months.
> > 
> > Tested-by: Alistair Popple <alistair@popple.id.au>
> 
> OK thanks.
> 
> To get it merged I'd like:
>  - always called after the barriers.
>  - no calls in loops, instead add a "count" field to the trace point and
>    when we call it multiple times in a loop we pass the count.
> 
> So you'd see entries something like:
> 
> <...>-5141  [062]  1354.486693: tlbie: lpid=0, local=1, rb=0x7b5d0ff874f11f1, rs=0, ric=0, prs=0, r=0, count=128
> 

I'll double check the patches and repost if required.

Balbir Singh.