Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755497Ab3J2OFo (ORCPT ); Tue, 29 Oct 2013 10:05:44 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:56300 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751951Ab3J2OFn (ORCPT ); Tue, 29 Oct 2013 10:05:43 -0400 X-Sasl-enc: veKdtOXv6J6WKTYQIfqZb2wMmsXeD3NfHVlykzqbZtIe 1383055541 Message-ID: <526FC0B2.6060206@iki.fi> Date: Tue, 29 Oct 2013 16:05:38 +0200 From: Pekka Enberg User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Hemant Kumar CC: David Ahern , Srikar Dronamraju , LKML , Peter Zijlstra , Oleg Nesterov , "hegdevasant@linux.vnet.ibm.com" , Ingo Molnar , "anton@redhat.com" , "systemtap@sourceware.org" , Namhyung Kim , Masami Hiramatsu , "aravinda@linux.vnet.ibm.com" Subject: Re: [PATCH v4 2/3] Support for perf to probe into SDT markers: References: <20131023044511.1886.82571.stgit@hemant-fedora> <20131023050502.1886.15779.stgit@hemant-fedora> <20131025125921.GA29424@linux.vnet.ibm.com> <526A8C2B.7000401@gmail.com> <526E24EA.2040701@iki.fi> <526E9808.4030607@gmail.com> <526EB0C3.2080304@iki.fi> <526F862E.9060203@linux.vnet.ibm.com> In-Reply-To: <526F862E.9060203@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1006 Lines: 27 On 10/29/2013 11:55 AM, Hemant Kumar wrote: > 1. Where this cache should be? Keeping it in tracing directory inside > the debugfs > directory should seem more feasible. And, shall this cache be shareable? You can't share all of the cache because otherwise you'll expose details on binaries that not everyone has access to. It might make sense to split the cache into two parts: system markers and user markers and share the former. > 2. perf record is a performance intensive process, can we allow the > delay due to > this searching process here? I think scanning is OK if the user specified a SDT markers but not otherwise. Perhaps you can use a bloom filter to quickly check if the user passed a SDT marker or not. Pekka -- 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/