Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752344AbbGWJEc (ORCPT ); Thu, 23 Jul 2015 05:04:32 -0400 Received: from ozlabs.org ([103.22.144.67]:38516 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751173AbbGWJE1 (ORCPT ); Thu, 23 Jul 2015 05:04:27 -0400 Message-ID: <1437642259.29271.1.camel@ellerman.id.au> Subject: Re: [PATCH v5 6/7] powerpc/powernv: generic nest pmu event functions From: Michael Ellerman To: Madhavan Srinivasan Cc: Daniel Axtens , linux-kernel@vger.kernel.org, Stephane Eranian , Paul Mackerras , Anton Blanchard , Sukadev Bhattiprolu , linuxppc-dev@lists.ozlabs.org, Anshuman Khandual Date: Thu, 23 Jul 2015 19:04:19 +1000 In-Reply-To: <55B08D4C.7050104@linux.vnet.ibm.com> References: <1437045206-7491-1-git-send-email-maddy@linux.vnet.ibm.com> <1437045206-7491-7-git-send-email-maddy@linux.vnet.ibm.com> <1437540961.30906.39.camel@axtens.net> <55B08D4C.7050104@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.10-0ubuntu1~14.10.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1468 Lines: 41 On Thu, 2015-07-23 at 12:14 +0530, Madhavan Srinivasan wrote: > > On Wednesday 22 July 2015 10:26 AM, Daniel Axtens wrote: > >> +static void p8_nest_read_counter(struct perf_event *event) > >> +{ > >> + uint64_t *addr; > >> + u64 data = 0; > > You've got a u64 and a uint64_t, and then... > >> + > >> + addr = (u64 *)event->hw.event_base; > > ... you cast to event_base to a u64 pointer, which you assign to a > > uint64_t pointer. > >> + data = __be64_to_cpu(*addr); > > And now you dereference the pointer. > > Could you just have: > > data = __be64_to_cpu(*event->hw.event_base); > >> + local64_set(&event->hw.prev_count, data); > >> +} > >> + > >> +static void p8_nest_perf_event_update(struct perf_event *event) > >> +{ > >> + u64 counter_prev, counter_new, final_count; > >> + uint64_t *addr; > >> + > >> + addr = (uint64_t *)event->hw.event_base; > > Here at least the cast type is the same as the type of addr, but again, > > why do you need the different types, and why local variable? > > Damn sorry, copy paste errors. When I added debug prints i messed > the type case in both the functions. I will make them as uint64_t. No please use u64/u32 etc. Most code in powerpc does and I prefer them. cheers -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/