From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E88BBC28CC0 for ; Thu, 30 May 2019 15:52:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8F0925B53 for ; Thu, 30 May 2019 15:52:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726558AbfE3Pwo (ORCPT ); Thu, 30 May 2019 11:52:44 -0400 Received: from foss.arm.com ([217.140.101.70]:38952 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725961AbfE3Pwn (ORCPT ); Thu, 30 May 2019 11:52:43 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5546C341; Thu, 30 May 2019 08:52:43 -0700 (PDT) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 53F3F3F59C; Thu, 30 May 2019 08:52:42 -0700 (PDT) Subject: Re: [PATCH 1/4] coresight: tmc-etr: Do not call smp_processor_id() from preemptible To: robin.murphy@arm.com, mathieu.poirier@linaro.org Cc: coresight@lists.linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <1557480663-16759-1-git-send-email-suzuki.poulose@arm.com> <1557480663-16759-2-git-send-email-suzuki.poulose@arm.com> <319d4d63-326b-9bb5-6a24-f7aa8ec549f9@arm.com> From: Suzuki K Poulose Message-ID: Date: Thu, 30 May 2019 16:52:40 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <319d4d63-326b-9bb5-6a24-f7aa8ec549f9@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Robin, On 10/05/2019 11:38, Robin Murphy wrote: > Hi Suzuki, > > On 10/05/2019 10:31, Suzuki K Poulose wrote: >> Instead of using smp_processor_id() to figure out the node, >> use the numa_node_id() for the current CPU node to avoid >> splats like : > >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> index 793639f..cae9d8a 100644 >> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c >> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c >> @@ -1323,13 +1323,11 @@ static struct etr_perf_buffer * >> tmc_etr_setup_perf_buf(struct tmc_drvdata *drvdata, struct perf_event *event, >> int nr_pages, void **pages, bool snapshot) >> { >> - int node, cpu = event->cpu; >> + int node; >> struct etr_buf *etr_buf; >> struct etr_perf_buffer *etr_perf; >> >> - if (cpu == -1) >> - cpu = smp_processor_id(); >> - node = cpu_to_node(cpu); >> + node = (event->cpu == -1) ? numa_node_id() : cpu_to_node(event->cpu); > > If cpu == -1 represents a "don't care" scenario, it might be clearer to > just use NUMA_NO_NODE instead, and let the allocator handle it. Thanks for the suggestion, will use that instead Cheers Suzuki