From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx163.postini.com [74.125.245.163]) by kanga.kvack.org (Postfix) with SMTP id 14F4A6B004D for ; Fri, 6 Jan 2012 06:16:41 -0500 (EST) Received: from /spool/local by e5.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 6 Jan 2012 06:16:38 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q06BFfgw409118 for ; Fri, 6 Jan 2012 06:15:41 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q06BFdUJ009957 for ; Fri, 6 Jan 2012 09:15:41 -0200 Date: Fri, 6 Jan 2012 16:38:24 +0530 From: Srikar Dronamraju Subject: Re: [PATCH v8 3.2.0-rc5 1/9] uprobes: Install and remove breakpoints. Message-ID: <20120106110824.GD14946@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20111216122756.2085.95791.sendpatchset@srdronam.in.ibm.com> <20111216122808.2085.76986.sendpatchset@srdronam.in.ibm.com> <1325695788.2697.3.camel@twins> <20120106061407.GC14946@linux.vnet.ibm.com> <1325847461.2442.4.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1325847461.2442.4.camel@twins> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Linus Torvalds , Oleg Nesterov , Ingo Molnar , Andrew Morton , LKML , Linux-mm , Andi Kleen , Christoph Hellwig , Steven Rostedt , Roland McGrath , Thomas Gleixner , Masami Hiramatsu , Arnaldo Carvalho de Melo , Anton Arapov , Ananth N Mavinakayanahalli , Jim Keniston , Stephen Rothwell * Peter Zijlstra [2012-01-06 11:57:41]: > On Fri, 2012-01-06 at 11:44 +0530, Srikar Dronamraju wrote: > > - consumers for the uprobe is NULL, so mmap_uprobe will not > > insert new breakpoints which correspond to this uprobe until > > or unless another consumer gets added for the same probe. > > > > - If a new consumer gets added for this probe, we reuse the > > uprobe struct. > > Ok, and when we install a new 'first' consumer we'll again try and > install all breakpoints ignoring those that were already there? > Yes, We install breakpoints as if its the first time a probe has been requested to be installed, including setting the UPROBES_RUN_HANDLER flag. We do check if existing breakpoints are around during the actual insertion, in which case install_breakpoint() will return -EEXIST. However register assumes EEXIST to be non-fatal, and continues as if its successful. -- Thanks and Regards Srikar -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org