From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751135AbdFAM50 (ORCPT ); Thu, 1 Jun 2017 08:57:26 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:34507 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbdFAM5Y (ORCPT ); Thu, 1 Jun 2017 08:57:24 -0400 Subject: Re: [RFC PATCH 00/10] x86: undwarf unwinder To: Josh Poimboeuf Cc: Peter Zijlstra , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Linus Torvalds , Andy Lutomirski , "H. Peter Anvin" References: <20170601060824.wv2go3adbvx5ptmt@gmail.com> <20170601115819.3twoowcnvtrfzjzr@treble> <20170601121721.lezoecnyah3aic6a@hirez.programming.kicks-ass.net> <20170601125204.kzozuzvw3mg37brn@treble> From: Jiri Slaby Message-ID: Date: Thu, 1 Jun 2017 14:57:21 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <20170601125204.kzozuzvw3mg37brn@treble> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/01/2017, 02:52 PM, Josh Poimboeuf wrote: >> This is ~ 20 times faster than my DWARF unwinder by a quick measurement >> (20000 calls to save_stack_trace via single vfs_write). > > Wow! BTW the most time spent when unwinding DWARF was in those routines decrypting uleb/sleb128 into u/longs. thanks, -- js suse labs