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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 4DDB5CA9ECF for ; Fri, 1 Nov 2019 10:54:35 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1FFF42086D for ; Fri, 1 Nov 2019 10:54:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="cmUdfmTM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FFF42086D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=WsJvj1m6xlMGCN0Oc4NwJebcn8CQfLY8ILH4DHPscYA=; b=cmUdfmTMl9bC6BdAR8tedGNaV J4SUE44J4Gc+UTlwBxCBBiugSvV9siAg9XjrHY0Y83oN6Dr3CIKqcfNIJCjr5U1xyGG5pbct3HNzc 3yIjGAj170ujkkajil0DXzUcn74moLfuiDPSI+KPJlLtbYRzJYOU1jqxRt8UOUkYPxRhPSJWiofis g2MGjHNRFYA9pxJHDSh5JHRtwhks91cgUuxj8OhCFrHHxAtYJb2oaKGOXCKJWLHPJD3OwR7+EIUiK vroOuYeoSuSNr12kPYYYGLFaqSaWic0aynwddkGE2RU2FPAnX6xoH5/bgcvsoDhnJm+FiaORqAWXq nlacYhvHw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQUZe-0001Y3-JG; Fri, 01 Nov 2019 10:54:34 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iQUZa-0001Wt-Gq for linux-arm-kernel@lists.infradead.org; Fri, 01 Nov 2019 10:54:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0DED71FB; Fri, 1 Nov 2019 03:54:27 -0700 (PDT) Received: from [192.168.1.124] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0AD8E3F6C4; Fri, 1 Nov 2019 03:54:25 -0700 (PDT) Subject: Re: [PATCH] arm64: perf: Simplify the ARMv8 PMUv3 event attributes To: Will Deacon , Mark Rutland References: <1572407177-48229-1-git-send-email-zhangshaokun@hisilicon.com> <20191031160804.GA28325@willie-the-truck> <20191101085319.GA3508@blommer> <20191101103616.GA2392@willie-the-truck> From: Robin Murphy Message-ID: Date: Fri, 1 Nov 2019 10:54:21 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <20191101103616.GA2392@willie-the-truck> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191101_035430_601011_5D65A766 X-CRM114-Status: GOOD ( 16.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Shaokun Zhang , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2019-11-01 10:36 am, Will Deacon wrote: > On Fri, Nov 01, 2019 at 08:53:19AM +0000, Mark Rutland wrote: >> On Thu, Oct 31, 2019 at 04:08:04PM +0000, Will Deacon wrote: >>> On Wed, Oct 30, 2019 at 11:46:17AM +0800, Shaokun Zhang wrote: >>>> For each PMU event, there is a ARMV8_EVENT_ATTR(xx, XX) and >>>> &armv8_event_attr_xx.attr.attr. Let's redefine the ARMV8_EVENT_ATTR >>>> to simplify the armv8_pmuv3_event_attrs. >>>> >>>> Cc: Will Deacon >>>> Cc: Mark Rutland >>>> Signed-off-by: Shaokun Zhang >>>> --- >>>> arch/arm64/kernel/perf_event.c | 189 ++++++++++++++--------------------------- >>>> 1 file changed, 65 insertions(+), 124 deletions(-) >>>> >>>> diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c >>>> index a0b4f1bca491..d0f084939bcf 100644 >>>> --- a/arch/arm64/kernel/perf_event.c >>>> +++ b/arch/arm64/kernel/perf_event.c >>>> @@ -159,132 +159,73 @@ armv8pmu_events_sysfs_show(struct device *dev, >>>> } >>> >>> [...] >>> >>>> + (&((struct perf_pmu_events_attr[]) { \ >>>> + { .attr = __ATTR(name, 0444, armv8pmu_events_sysfs_show, NULL), \ >>>> + .id = config, } \ >>>> + })[0].attr.attr) >>> >>> I don't get the need for the array here. Why can't you do: >>> >>> (&((struct perf_pmu_events_attr) { >>> .attr = ..., >>> .id = ..., >>> }).attr.attr) >> >> You need want &(obj.attr.attr) rather than &(obj).attr.attr, i.e. >> >> #define ARMV8_EVENT_ATTR(name, config) \ >> (&((struct perf_pmu_events_attr) { \ >> .attr = __ATTR(name, 0444, armv8pmu_events_sysfs_show, NULL), \ >> .id = config, \ >> }.attr.attr)) >> >> ... which compiles for me. > > Weird, the following compiles fine for me with both GCC and clang: > > #define ARMV8_EVENT_ATTR(name, config) \ > (&((struct perf_pmu_events_attr) { \ > .attr = __ATTR(name, 0444, armv8pmu_events_sysfs_show, NULL), \ > .id = config, \ > }).attr.attr) You know that the expressions are equivalent because unary "&" has lower precedence than ".", right? ;) Robin. >> It'd be worth checking that yields a working data structure at runtime. > > ...and perf list works as expected. > > Will > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel