From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932781AbeBLWWE (ORCPT ); Mon, 12 Feb 2018 17:22:04 -0500 Received: from mga07.intel.com ([134.134.136.100]:64295 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932738AbeBLWVw (ORCPT ); Mon, 12 Feb 2018 17:21:52 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,504,1511856000"; d="scan'208";a="29490605" From: kan.liang@linux.intel.com To: peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org Cc: acme@kernel.org, tglx@linutronix.de, jolsa@redhat.com, eranian@google.com, ak@linux.intel.com, Kan Liang Subject: [PATCH V4 5/5] perf/x86: Fix: disable userspace RDPMC usage for large PEBS Date: Mon, 12 Feb 2018 14:20:35 -0800 Message-Id: <1518474035-21006-6-git-send-email-kan.liang@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1518474035-21006-1-git-send-email-kan.liang@linux.intel.com> References: <1518474035-21006-1-git-send-email-kan.liang@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kan Liang The userspace RDPMC usage never works for large PEBS since the large PEBS is introduced by commit b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)") When the PEBS interrupt threshold is larger than one, there is no way to get exact auto-reload times and value for userspace RDPMC. Disable the userspace RDPMC usage when large PEBS is enabled. For the PEBS interrupt threshold equals to one, even it's auto-reload event, it doesn't need to disable the userspace RDPMC. It works well. Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)") Signed-off-by: Kan Liang --- arch/x86/events/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 00a6251..9c86e10 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2117,7 +2117,8 @@ static int x86_pmu_event_init(struct perf_event *event) event->destroy(event); } - if (READ_ONCE(x86_pmu.attr_rdpmc)) + if (READ_ONCE(x86_pmu.attr_rdpmc) && + !(event->hw.flags & PERF_X86_EVENT_FREERUNNING)) event->hw.flags |= PERF_X86_EVENT_RDPMC_ALLOWED; return err; -- 2.7.4