From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 29 Apr 2008 12:09:51 -0700 (PDT) From: Christoph Lameter Subject: Re: [2/2] vmallocinfo: Add caller information In-Reply-To: <20080428140026.32aaf3bf@infradead.org> Message-ID: References: <20080318222701.788442216@sgi.com> <20080318222827.519656153@sgi.com> <20080429084854.GA14913@elte.hu> <20080428124849.4959c419@infradead.org> <20080428140026.32aaf3bf@infradead.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Arjan van de Ven Cc: Ingo Molnar , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Linus Torvalds , Peter Zijlstra List-ID: On Mon, 28 Apr 2008, Arjan van de Ven wrote: > > Hmmm... Why do we have CONFIG_FRAMEPOINTER then? > > to make the backtraces more accurate. Well so we display out of whack backtraces? There are also issues on platforms that do not have a stack in the classic sense (rotating register file on IA64 and Sparc64 f.e.). Determining a backtrace can be very expensive. > > The current implementation of vmalloc_caller() follows what we have > > done with kmalloc_track_caller. Its low overhead and always on. > > stacktraces aren't entirely free, the cost is O(nr of modules) unfortunately ;( The current implementation /proc/vmallocinfo avoids these issues and with just one caller address it can print one line per vmalloc request. -- 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