Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753353AbaJTJYX (ORCPT ); Mon, 20 Oct 2014 05:24:23 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:58561 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752854AbaJTJYU (ORCPT ); Mon, 20 Oct 2014 05:24:20 -0400 Date: Mon, 20 Oct 2014 11:24:13 +0200 From: Martin Schwidefsky To: Peter Zijlstra Cc: Andy Lutomirski , Valdis Kletnieks , "linux-kernel@vger.kernel.org" , Paul Mackerras , Arnaldo Carvalho de Melo , Ingo Molnar , Kees Cook , Andrea Arcangeli , Erik Bosman , mpe@ellerman.id.au, anton@samba.org, brueckner@linux.vnet.ibm.com Subject: Re: [RFC 5/5] x86,perf: Only allow rdpmc if a perf_event is mapped Message-ID: <20141020112413.56450095@mschwide> In-Reply-To: <20141020084813.GB3219@twins.programming.kicks-ass.net> References: <20141019213534.GG23531@worktop.programming.kicks-ass.net> <20141020084813.GB3219@twins.programming.kicks-ass.net> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14102009-0013-0000-0000-00000181E418 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 20 Oct 2014 10:48:13 +0200 Peter Zijlstra wrote: > > - cpumsf_pmu_event_idx is the same as power_pmu_event_idx. > > Oh cute, lets ask the s390 people, do you guys have a userspace > instruction to read the actual counter value? The "extract cpu counter" ECCTR instruction can be authorized to be used in user-space with a bit in CR0. With the current code this bit is not set, the cpu measurement facility is not usable in user space without a patch to the kernel. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/