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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT 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 95C60C04AB1 for ; Thu, 9 May 2019 18:43:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B81F2182B for ; Thu, 9 May 2019 18:43:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557427439; bh=DOm656UkymZRCMYjy77wewMGZDxOeHkGO/azjVfI2RU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uCGE3r0w4PrVMTPE8CAMUwZ2q5/jgcSdINYwFlnTDsIUyfOjG4ejYFb4NaZmq/2V8 4Eq23woWtOVffpQ+AyJWxcXVc2QRtrJy/okYPFANqOA+2ORqvA3/Z6ipcqhaiLHUR2 ZRSTfNF1fcHwb0nu52x3TkXrQGGmJ+uAtWsr/vtg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726831AbfEISn6 (ORCPT ); Thu, 9 May 2019 14:43:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:34994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726620AbfEISn5 (ORCPT ); Thu, 9 May 2019 14:43:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C6EE6217F5; Thu, 9 May 2019 18:43:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557427436; bh=DOm656UkymZRCMYjy77wewMGZDxOeHkGO/azjVfI2RU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cc9AIsDmHHM3Z5fBYJ2G9IVxVka30r3Lju9IoV6pQeR6W4HX1JokunMblMtIAemak d9PQ0sLZBlFn2qymm+w3ei0sEoVtxtXP44WKQYKsPZMPLSKe5HLwz+OUliiOynPJQo WVSnOvOnbwX8XuUKuSBGdJ47BisxsA5hu8A7lXmc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephane Eranian , "Peter Zijlstra (Intel)" , Andi Kleen , Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Thomas Gleixner , Vince Weaver , kan.liang@intel.com, Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 10/28] perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS Date: Thu, 9 May 2019 20:42:02 +0200 Message-Id: <20190509181252.386241132@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190509181247.647767531@linuxfoundation.org> References: <20190509181247.647767531@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 583feb08e7f7ac9d533b446882eb3a54737a6dbb ] When an event is programmed with attr.wakeup_events=N (N>0), it means the caller is interested in getting a user level notification after N samples have been recorded in the kernel sampling buffer. With precise events on Intel processors, the kernel uses PEBS. The kernel tries minimize sampling overhead by verifying if the event configuration is compatible with multi-entry PEBS mode. If so, the kernel is notified only when the buffer has reached its threshold. Other PEBS operates in single-entry mode, the kenrel is notified for each PEBS sample. The problem is that the current implementation look at frequency mode and event sample_type but ignores the wakeup_events field. Thus, it may not be possible to receive a notification after each precise event. This patch fixes this problem by disabling multi-entry PEBS if wakeup_events is non-zero. Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Andi Kleen Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vince Weaver Cc: kan.liang@intel.com Link: https://lkml.kernel.org/r/20190306195048.189514-1-eranian@google.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- arch/x86/events/intel/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 098ab775135fd..a30829052a006 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2867,7 +2867,7 @@ static int intel_pmu_hw_config(struct perf_event *event) return ret; if (event->attr.precise_ip) { - if (!event->attr.freq) { + if (!(event->attr.freq || event->attr.wakeup_events)) { event->hw.flags |= PERF_X86_EVENT_AUTO_RELOAD; if (!(event->attr.sample_type & ~intel_pmu_free_running_flags(event))) -- 2.20.1