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,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 459D4C04AB1 for ; Thu, 9 May 2019 18:48:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 187C4217D7 for ; Thu, 9 May 2019 18:48:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557427684; bh=e6xqg4Ow/x1yX/utboduXIpg42hiUbk/k2nfCwWgXpw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ozax/CYluSCXHn6KrPkSuHHnhejfNktSHCJr9XiqjRDq6iSXaKrSdwXNit1xQltvm XNYJYLu5tLIK/xo2LC62YZL13Qfk+ZjWghAAYn+5RYUjKqvyahCQdH444eiIOdHXJf q8zt5ScGsUFLIb88Xa0DVd+KUykXEVq+BGRcWdG4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727938AbfEISsC (ORCPT ); Thu, 9 May 2019 14:48:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:40756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727925AbfEISsB (ORCPT ); Thu, 9 May 2019 14:48:01 -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 E5D3320578; Thu, 9 May 2019 18:47:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557427680; bh=e6xqg4Ow/x1yX/utboduXIpg42hiUbk/k2nfCwWgXpw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V7CDMBTtM8LXtOG0sM4RopjpRr07oTtKP7HZNSw9ldCoRAXi+1tiKeikgrFHzKZvJ 5R7+HinMs4vrxFzdcFWpvncIzqtntKK++NrFsZkPQ5Rn4GdzFmSQ4K+557uinaZhCy vgkkKCH35aOI852daKRJzdcm9TDlDA+UOn5gk97Q= 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 4.19 29/66] perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS Date: Thu, 9 May 2019 20:42:04 +0200 Message-Id: <20190509181304.958580335@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190509181301.719249738@linuxfoundation.org> References: <20190509181301.719249738@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 3dd204d1dd194..26432ee4590e3 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3068,7 +3068,7 @@ 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_large_pebs_flags(event))) -- 2.20.1