From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757951AbcG0S2M (ORCPT ); Wed, 27 Jul 2016 14:28:12 -0400 Received: from smtprelay0245.hostedemail.com ([216.40.44.245]:53545 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756828AbcG0S2H (ORCPT ); Wed, 27 Jul 2016 14:28:07 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:982:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2693:3138:3139:3140:3141:3142:3353:3622:3865:3866:3867:3868:3870:3871:3872:3873:3874:4321:5007:6261:6742:7875:8531:9040:10004:10226:10400:10848:10967:11232:11658:11914:12517:12519:12740:13069:13161:13229:13311:13357:13439:14096:14097:14181:14659:14721:21080:30054:30075:30083:30090:30091,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:2,LUA_SUMMARY:none X-HE-Tag: help96_be927533ff40 X-Filterd-Recvd-Size: 2740 Date: Wed, 27 Jul 2016 14:28:00 -0400 From: Steven Rostedt To: Rik van Riel Cc: Michal Hocko , Janani Ravichandran , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hannes@compxchg.org, vdavydov@virtuozzo.com, vbabka@suse.cz, mgorman@techsingularity.net, kirill.shutemov@linux.intel.com, bywxiaobai@163.com Subject: Re: [PATCH 1/2] mm: page_alloc.c: Add tracepoints for slowpath Message-ID: <20160727142800.14bd93d0@gandalf.local.home> In-Reply-To: <1469643382.10218.20.camel@surriel.com> References: <6b12aed89ad75cb2b3525a24265fa1d622409b42.1469629027.git.janani.rvchndrn@gmail.com> <20160727163351.GC21859@dhcp22.suse.cz> <1469643382.10218.20.camel@surriel.com> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 Jul 2016 14:16:22 -0400 Rik van Riel wrote: > As for the function tracer, I wish I had known > about that! The kernel (and just the tracing infrastructure) is too big to know everything that is there. > > That looks like it should provide the info that > Janani needs to write her memory allocation latency > tracing script/tool. > > As her Outreachy mentor, I should probably apologize > for potentially having sent her down the wrong path > with tracepoints, and I hope it has been an > educational trip at least :) > No, it was a perfect example of how we work, and I don't see this as a wrong path. It's a good learning tool because that patch is exactly what someone wanting to do a specific task will probably do as their first attempt. There should be no shame in sending out a patch and have feedback on another way to accomplish the same thing that doesn't impact the system as much. As stated above, the kernel is too big to know everything that needs to be done. Thus, kernel development is really about trial and error. Send out what works for you, and then take feedback from those that know their system better than you to make your patch better. That's how the workflow should happen on a daily basis. And is exactly how I operate. There's lots of patches that I send out to other maintainers that end up being something complete different because I don't know their systems as well as they do. -- Steve