From patchwork Thu Oct 12 12:30:34 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 115616 Delivered-To: patch@linaro.org Received: by 10.140.22.163 with SMTP id 32csp1884173qgn; Thu, 12 Oct 2017 05:30:59 -0700 (PDT) X-Google-Smtp-Source: AOwi7QBmIbB2S9fqFWeMQVRsuHb2kWAQQElJkmpK0SZJNpBKB+tCK/zJqf8khMlx4JVl+WnAI2Af X-Received: by 10.101.86.135 with SMTP id v7mr103324pgs.135.1507811459467; Thu, 12 Oct 2017 05:30:59 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1507811459; cv=none; d=google.com; s=arc-20160816; b=Gl3f8SRjFhDxxpcd9+c5BwKTZtwh4sNFqm/Cd3mLgT3ddYrm4rI7Ya1JaE1DPZ4pqV AfYBppn0mUIr3/2X3E24rknpBR7SXYByStb8uPXmrE1aiHCUOsn8yCPVv21AnYFN3ycZ TiVEF/P+xya3w6F2fgwtfentR9tLxN8qY0spH09PjlWqe6vG1H9daT4WoPDU9ocaju6Z FnD+BYmyvVyfdzc2fmhC3HsBHpNYFxzdlLpWyuwF0/dwDm1hRxEDgMMhmxnYIlNlVAuK EgsapSQY3qJrQH56re0RSMxw+ssNY7VHYIuEh0Ul0GKUeWER/rgg/kVjETRYWtQ7pZFw D8Jg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=WCWpyOKXFtEUm65Fhm/4hXbSu9GyJqgc/s1XuTQ6B6Q=; b=CEQGOKiuqccK5nAA7v6BwICG5CAuHEjR5va0euU5ntZ1Ux+sNYTaVLTCmok5VAlGs4 l3+Lqt44lJE5Sx50Er1+tSabm1cmg47zzFeetO9BMIHm0N2u2CFYASfS6yxu/TfYzkvY tGGJ9ANI0xhk3x0wkTRxPAkFitqcFouvdCngf+k4Pv8Mky6qmW8VA4hNZ3Vk4JALU9oV Usrl4BtHuKa7rMltaYPzWxPwfcfDmv4ajTzjdar1SxFIk1v7Ih04GSRX8SoW+tf3N+rv qQwxHVAwathodb2Ujl0fB/lJNFDFmKuYCI3YYBDOu+VfQN1dYrxjKNsVYn/tkERY78vy Wlug== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id y13si11281277pgc.792.2017.10.12.05.30.59; Thu, 12 Oct 2017 05:30:59 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757473AbdJLMan (ORCPT + 27 others); Thu, 12 Oct 2017 08:30:43 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:45858 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756721AbdJLMah (ORCPT ); Thu, 12 Oct 2017 08:30:37 -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 1B53E164F; Thu, 12 Oct 2017 05:30:37 -0700 (PDT) Received: from edgewater-inn.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E12103F599; Thu, 12 Oct 2017 05:30:36 -0700 (PDT) Received: by edgewater-inn.cambridge.arm.com (Postfix, from userid 1000) id 905011AE2E48; Thu, 12 Oct 2017 13:30:40 +0100 (BST) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Cc: marc.zyngier@arm.com, mark.rutland@arm.com, kim.phillips@arm.com, tglx@linutronix.de, peterz@infradead.org, alexander.shishkin@linux.intel.com, robh@kernel.org, suzuki.poulose@arm.com, pawel.moll@arm.com, mathieu.poirier@linaro.org, mingo@redhat.com, linux-kernel@vger.kernel.org, Will Deacon Subject: [PATCH v6 3/7] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples Date: Thu, 12 Oct 2017 13:30:34 +0100 Message-Id: <1507811438-2267-4-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1507811438-2267-1-git-send-email-will.deacon@arm.com> References: <1507811438-2267-1-git-send-email-will.deacon@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The ARM SPE architecture permits an implementation to ignore a sample if the sample is due to be taken whilst another sample is already being produced. In this case, it is desirable to report the collision to userspace, as they may want to lower the sample period. This patch adds a PERF_AUX_FLAG_COLLISION flag, so that such events can be relayed to userspace. Acked-by: Peter Zijlstra Signed-off-by: Will Deacon --- include/uapi/linux/perf_event.h | 1 + 1 file changed, 1 insertion(+) -- 2.1.4 diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 140ae638cfd6..7ca1b22ea417 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -941,6 +941,7 @@ enum perf_callchain_context { #define PERF_AUX_FLAG_TRUNCATED 0x01 /* record was truncated to fit */ #define PERF_AUX_FLAG_OVERWRITE 0x02 /* snapshot from overwrite mode */ #define PERF_AUX_FLAG_PARTIAL 0x04 /* record contains gaps */ +#define PERF_AUX_FLAG_COLLISION 0x08 /* sample collided with another */ #define PERF_FLAG_FD_NO_GROUP (1UL << 0) #define PERF_FLAG_FD_OUTPUT (1UL << 1)