From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755157AbcHATwO (ORCPT ); Mon, 1 Aug 2016 15:52:14 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:55418 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755106AbcHATwD (ORCPT ); Mon, 1 Aug 2016 15:52:03 -0400 Subject: Re: [PACTH v1] trace: Add trace events for open(), exec() and uselib() To: Al Viro References: <1470072340-17748-1-git-send-email-robert.foss@collabora.com> <20160801181014.GB2356@ZenIV.linux.org.uk> Cc: rostedt@goodmis.org, mingo@redhat.com, scott@ubuntu.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org From: Robert Foss Message-ID: Date: Mon, 1 Aug 2016 15:51:54 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160801181014.GB2356@ZenIV.linux.org.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016-08-01 02:10 PM, Al Viro wrote: > On Mon, Aug 01, 2016 at 01:25:40PM -0400, robert.foss@collabora.com wrote: >> From: Scott James Remnant >> >> This patch uses TRACE_EVENT to add tracepoints for the open(), >> exec() and uselib() syscalls so that ureadahead can cheaply trace >> the boot sequence to determine what to read to speed up the next. > > NAK. No Tracepoints In VFS. Not going to happen - any tracepoint can all too > easily become a cast-in-stone userland ABI. > Hey Al, I'm slightly unfamiliar with this territory, so please forgive my lack of knowledge of this topic. What is the negative side of having tracepoint be a permanent fixture in the VFS ABI? And how is VFS different from other subsystems in that regard? Rob.