From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 26 Aug 2005 16:05:50 -0700 (PDT) From: Christoph Lameter Subject: Re:[PATCH] Only process_die notifier in ia64_do_page_fault if KPROBES is configured. In-Reply-To: <200508262246.j7QMkEoT013490@linux.jf.intel.com> Message-ID: References: <200508262246.j7QMkEoT013490@linux.jf.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Rusty Lynch Cc: linux-mm@kvack.org, prasanna@in.ibm.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, anil.s.keshavamurthy@intel.com List-ID: On Fri, 26 Aug 2005, Rusty Lynch wrote: > Just to be sure everyone understands the overhead involved, kprobes only > registers a single notifier. If kprobes is disabled (CONFIG_KPROBES is > off) then the overhead on a page fault is the overhead to execute an empty > notifier chain. Its the overhead of using registers to pass parameters, performing a function call that does nothing etc. A waste of computing resources. All of that unconditionally in a performance critical execution path that is executed a gazillion times for an optional feature that I frankly find not useful at all and that is disabled by default. -- 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/ . Don't email: email@kvack.org