Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755053AbbDTWIu (ORCPT ); Mon, 20 Apr 2015 18:08:50 -0400 Received: from mail-lb0-f177.google.com ([209.85.217.177]:34333 "EHLO mail-lb0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751650AbbDTWIs (ORCPT ); Mon, 20 Apr 2015 18:08:48 -0400 MIME-Version: 1.0 In-Reply-To: <20150420215645.GC10191@pd.tnic> References: <1429565231-4609-1-git-send-email-hagen@jauu.net> <20150420215645.GC10191@pd.tnic> Date: Tue, 21 Apr 2015 00:08:46 +0200 Message-ID: Subject: Re: [PATCH RFC] x86: enforce inlining for atomics From: Hagen Paul Pfeifer To: Borislav Petkov Cc: "linux-kernel@vger.kernel.org" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1025 Lines: 28 On 20 April 2015 at 23:56, Borislav Petkov wrote: > Hmm, that must be config-specific as doing > > objdump -D vmlinux | grep -i "atomic_add" > > here gives me only "drm_atomic_add_affected_connectors" matches. > > It probably gets inlined here always... Probably, the config is allyesconfig minus trace/kernel adress sanitizer and gcov related options. > Other than that, this patch should actually even show some speedup as > we're getting rid of the stack preparation and function call overhead. > Have you done any benchmarks with it? No, but I am sure that a benchmark should show at least theoretically better perf numbers. But the numbers should be the measurement uncertainty range. The avoided cache line miss should be the greatest perf effect. Hagen -- 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/