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=-8.2 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 988B8CA9EBB for ; Mon, 4 Nov 2019 01:03:10 +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 5DE2A222D1 for ; Mon, 4 Nov 2019 01:03:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="V5Qn0AkJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DE2A222D1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hisilicon.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-Transfer-Encoding:Content-Type: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=rYhwxJr3pAfeohpGSyc2S6c/UMa6ZU/me+bhAbYKYNk=; b=V5Qn0AkJN10Om4 PAHVGR1EhQv7CGte3y6b7WeRju3lLeE2YUJd8fUuxOpQLRwzvPDCWpsb0yhCe8CBZCpDwTssAfvQ6 r2A8p7dL+VlHKQdyAf6XkihswgJHYgGDgRLY6FdQyo94T1rVu3T5uXtZNssdf+1Fx2KfWYOMLfm7b GmhaukKM9VrxpM8uQBzB95PxwbzTv+ckAbYg48dgUn5tRm5TWAPQdC1/avLo4VRQgJSUvmpT+bG/L ZNDd8yC229hNiLoqEgWiwgi1oJ7i0XhI/zQqFR5tzEC/LRD3BOqfK/ap0cXIvl9A7TkBxl76VOQ3F rV7P92MNv44sr2SwvEhA==; 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 1iRQlx-00027a-O2; Mon, 04 Nov 2019 01:03:09 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iRQlt-0001yn-J1 for linux-arm-kernel@lists.infradead.org; Mon, 04 Nov 2019 01:03:07 +0000 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 8A1BFB88D172B7DC17EA; Mon, 4 Nov 2019 09:02:49 +0800 (CST) Received: from [127.0.0.1] (10.74.221.148) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.439.0; Mon, 4 Nov 2019 09:02:46 +0800 Subject: Re: [PATCH] arm64: perf: Simplify the ARMv8 PMUv3 event attributes To: Will Deacon , Robin Murphy References: <1572407177-48229-1-git-send-email-zhangshaokun@hisilicon.com> <20191031160804.GA28325@willie-the-truck> <20191101085319.GA3508@blommer> <20191101103616.GA2392@willie-the-truck> <20191101105557.GC2392@willie-the-truck> From: Shaokun Zhang Message-ID: <00880214-70ea-d374-7a42-fa25e8c21cb6@hisilicon.com> Date: Mon, 4 Nov 2019 09:02:47 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <20191101105557.GC2392@willie-the-truck> X-Originating-IP: [10.74.221.148] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191103_170305_802492_54A311FC X-CRM114-Status: GOOD ( 12.66 ) 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: Mark Rutland , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Will, On 2019/11/1 18:55, Will Deacon wrote: > On Fri, Nov 01, 2019 at 10:54:21AM +0000, Robin Murphy wrote: >> 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? ;) > > Right, which is why it's weird that Shaokun claims that the version I posted > doesn't compile. I assume it didn't build for Mark either, hence his extra The GCC version is gcc (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.10) 5.4.0 20160609. It's a little old ;-) Thanks, Shaokun > brackets. > > Will > > . > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel