Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757249Ab3FVLp1 (ORCPT ); Sat, 22 Jun 2013 07:45:27 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:2370 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756024Ab3FVLp0 (ORCPT ); Sat, 22 Jun 2013 07:45:26 -0400 X-Authority-Analysis: v=2.0 cv=KtrPKBqN c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=MIoFJYSRGoYA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=0ytn0xNaxVYA:10 a=Dpj0UFl6rbHliy2tjoIA:9 a=QEXdDO2ut3YA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-ID: <1371901523.18733.139.camel@gandalf.local.home> Subject: Re: [PATCH 03/11] tracing: add soft disable for syscall events From: Steven Rostedt To: Jovi Zhang Cc: "zhangwei(Jovi)" , Tom Zanussi , masami.hiramatsu.pt@hitachi.com, LKML , Oleg Nesterov Date: Sat, 22 Jun 2013 07:45:23 -0400 In-Reply-To: References: <51C3F866.4080705@huawei.com> <1371846146.18733.126.camel@gandalf.local.home> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-3 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1431 Lines: 39 On Sat, 2013-06-22 at 13:08 +0800, Jovi Zhang wrote: > > I would really like to make these smaller. They are made for every > > system call, and I consider tracing to always be added overhead. I hate > > it when we waste more memory for tracing as very few people use it > > (compared to those that use Linux). > > > > Is it possible to allocate this only when its first used? > > > > -- Steve > > I think the answer is yes. > > Compare with link ftrace_event_file with static syscall_metadata, another option > is put into structure trace_array, just like enabled_enter_syscalls and > enabled_exit_syscalls BITMAP already in there > (need change to dynamic allocated NR_syscalls array, just keep a > pointer in trace_array). > > Then in this way, there don't have any extra size overhead for static > syscall_metadata, > but need to allocate a array with NR_syscalls elements when first use > syscall tracing. > > which option do you prefer? steven. Hey, if it only allocates when tracing is used, that's a big plus. Tracing should be treated as a drug. Just like not allowing smoking in public places, only punish the users, not those that want to breath fresh air. -- Steve -- 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/