Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756227Ab1DZOG3 (ORCPT ); Tue, 26 Apr 2011 10:06:29 -0400 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:35971 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754361Ab1DZOG2 (ORCPT ); Tue, 26 Apr 2011 10:06:28 -0400 Date: Tue, 26 Apr 2011 16:05:57 +0200 From: Borislav Petkov To: Ingo Molnar Cc: Peter Zijlstra , Borislav Petkov , Arnaldo Carvalho de Melo , Steven Rostedt , Frederic Weisbecker , Tony Luck , Mauro Carvalho Chehab , David Ahern , EDAC devel , LKML Subject: Re: [PATCH 02/18] perf: Add persistent event facilities Message-ID: <20110426140557.GA24614@aftab> References: <1303576100-425-1-git-send-email-bp@amd64.org> <1303576100-425-3-git-send-email-bp@amd64.org> <1303815470.20212.260.camel@twins> <20110426124510.GB15076@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110426124510.GB15076@elte.hu> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2626 Lines: 64 On Tue, Apr 26, 2011 at 08:45:10AM -0400, Ingo Molnar wrote: > > * Peter Zijlstra wrote: > > > On Sat, 2011-04-23 at 18:28 +0200, Borislav Petkov wrote: > > > From: Borislav Petkov > > > > > > Add a barebones implementation for registering persistent events with > > > perf. For that, we don't destroy the buffers when they're unmapped and > > > we map them read-only so that multiple agents can access them. > > > > > > Signed-off-by: Borislav Petkov > > > --- > > > include/linux/perf_event.h | 22 ++++++++++++++++- > > > kernel/events/Makefile | 2 +- > > > kernel/events/core.c | 30 ++++++++++++++++++---- > > > kernel/events/persistent.c | 56 ++++++++++++++++++++++++++++++++++++++++++++ > > > 4 files changed, 102 insertions(+), 8 deletions(-) > > > create mode 100644 kernel/events/persistent.c > > > > > > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > > > index ee9f1e7..37bfae1 100644 > > > --- a/include/linux/perf_event.h > > > +++ b/include/linux/perf_event.h > > > @@ -216,8 +216,9 @@ struct perf_event_attr { > > > precise_ip : 2, /* skid constraint */ > > > mmap_data : 1, /* non-exec mmap data */ > > > sample_id_all : 1, /* sample_type all events */ > > > + persistent : 1, /* event always on */ > > > > But how will you find it again? > > > > Persistent yells filesystem to me, and while we didn't use relayfs for > > various reasons, I think we do need something like it at the current stage. > > eventfs or sysfs? > > We need VFS space for event hierarchy enumeration anyway (and move the current > debugfs bits there). Persistent events could show up in that hiearachy as well. I think we talked about this already in conjunction with moving event hierarchy to sysfs - there you can have a "persistent" node too so you can find it. Here's what we talked about then: https://lkml.org/lkml/2010/11/11/10 this and the following messages. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 -- 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/