From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH 1/2] tools, perf: Add a precise event qualifier v2 Date: Wed, 24 Jul 2013 00:51:50 +0200 Message-ID: <20130723225150.GT6123@two.firstfloor.org> References: <1374501138-13496-1-git-send-email-andi@firstfloor.org> <20130723060108.GA18396@tassilo.jf.intel.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: trinity-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vince Weaver Cc: Andi Kleen , Andi Kleen , acme@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Stephane Eranian , torvalds@linux-foundation.org, trinity@vger.kernel.org On Tue, Jul 23, 2013 at 05:27:43PM -0400, Vince Weaver wrote: > > I hate having to justify why breaking the ABI is unacceptable. Well it's a testing ABI, so we can do changes to it. I hope you're not suggesting that perf cannot be extended anymore. As you know, hardware PMUs are constantly evolving, and perf has evolve along with them to stay useful. > It breaks the ABI. The events/* sysfs files are documented as only > holding values for the bitfields described in format/*. Ok. Need to fix the documentation then for precise=1. I'll send patches. Also can add it to format/*, but since it's not in config* it will be an extension. Since it would be awkward to teach every parser about all the flags, we could add a "flags" field that is handled like config, and contains all the flags. So format/precise would be flags:15-16 on little endian. Looks good? > I'm a bit grumpy about this because I just finished fixing the fallout > from your last time breaking the ABI a few weeks ago when your broken code > started dumping non-hex fields into the sysfs event strings. I've learned Not sure what you're talking about? iirc the only recent sysfs change of mine merged recently was adding intx/intx_cp, and format files never have had hex numbers in it. > now that I have to go over your patches with a fine-tooth code because you > have no regard for the ABI. Any useful code review is appreciated. -Andi -- ak@linux.intel.com -- Speaking for myself only.