Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753703AbYK0PvI (ORCPT ); Thu, 27 Nov 2008 10:51:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751446AbYK0Puz (ORCPT ); Thu, 27 Nov 2008 10:50:55 -0500 Received: from ti-out-0910.google.com ([209.85.142.189]:31656 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751080AbYK0Puy (ORCPT ); Thu, 27 Nov 2008 10:50:54 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=ASkp5Pk2jIzqURxeWMcae2J0qYBDcEFVR7rTTacBcdKuD/pTLpShCVuRFORe1d/xi1 mZBRLJehgsV5inRcx0BhwGybU0TstgL+szKxePf6LFOp4LTIOT+QWTZyfpVriQ5Bczog xslGZGBO+mTOWbHtu+1gCRlAlWLN+9FcAN6q8= Date: Thu, 27 Nov 2008 23:50:47 +0800 From: walimis To: Steven Rostedt Cc: linux-kernel@vger.kernel.org Subject: Re: about use wild cards for set_ftrace_filter and so on Message-ID: <20081127155047.GB24616@ubuntu.mshome.net> References: <20081127152124.GA24616@ubuntu.mshome.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2489 Lines: 84 On Thu, Nov 27, 2008 at 10:34:19AM -0500, Steven Rostedt wrote: > >On Thu, 27 Nov 2008, walimis wrote: > >> >> I encountered an issue when using ftrace. >> We know that we can use wild cards to set set_ftrace_filter, but there's >> problem when using such as "echo h* > /debug/tracing/set_ftrace_filter". >> If there are files named with "h" prefix in current directory, echo "h*" >> will echo these files' name to set_ftrace_filter, not "h*". >> For example: >> >> #cat /debug/tracing/available_filter_functions |grep ^hr |wc -l >> 23 >> #ls >> #touch hraa hrdd >> #ls >> hraa hrdd >> #echo hr* > /debug/tracing/set_ftrace_filter >> #cat /debug/tracing/set_ftrace_filter >> >> No output in /debug/tracing/set_ftrace_filter! >> If we use "" to enclose wild cards, it works: >> >> #ls >> hraa hrdd >> #echo "hr*" > /debug/tracing/set_ftrace_filter >> #cat /debug/tracing/set_ftrace_filter |wc -l >> 23 >> >> This problem can lead to unexpected result if current directory has a >> lot of files. >> I suppose that we can add some notes to document, so a patch attached. > >Using TB? It's best to inline the patch, that way I can comment on it >better. Using mutt, but I don't know how to inline the patch now. > >Anyway, you should fix the example. I also recommend a single quote over >double, to prevent any other translation that bash might do. > >The example in ftrace.txt should be: > > # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter > > >Thanks, > >-- Steve > >/me goes back to eating turkeys. I only add a note, but I wonder whether enough. If needed, I can add a example to this document. Impact: imporve document Signed-off-by: walimis --- Documentation/ftrace.txt | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/Documentation/ftrace.txt b/Documentation/ftrace.txt index de05042..9735434 100644 --- a/Documentation/ftrace.txt +++ b/Documentation/ftrace.txt @@ -1251,6 +1251,9 @@ These are the only wild cards which are supported. * will not work. +Note: you'd better to use '' to enclose wild cards, otherwise in some +case you can't get the correct result. + # echo hrtimer_* > /debug/tracing/set_ftrace_filter Produces: -- 1.6.0.3 -- 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/