Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753572AbbG2Nbl (ORCPT ); Wed, 29 Jul 2015 09:31:41 -0400 Received: from mail-lb0-f170.google.com ([209.85.217.170]:34207 "EHLO mail-lb0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751753AbbG2Nbk (ORCPT ); Wed, 29 Jul 2015 09:31:40 -0400 Message-ID: <1438176656.18723.8.camel@ceres> Subject: Re: [PATCH] lib: Make _find_next_bit helper function inline From: Alexey Klimov To: Andrew Morton , Cassidy Burden Cc: Yury , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "David S. Miller" , Daniel Borkmann , Hannes Frederic Sowa , Lai Jiangshan , Mark Salter , AKASHI Takahiro , Thomas Graf , Valentin Rothberg , Chris Wilson Date: Wed, 29 Jul 2015 16:30:56 +0300 In-Reply-To: <20150728144537.67d46b5714c99d25f0bb33fb@linux-foundation.org> References: <1438110564-19932-1-git-send-email-cburden@codeaurora.org> <55B7F2C6.9010000@gmail.com> <20150728144537.67d46b5714c99d25f0bb33fb@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1445 Lines: 61 On Вт., 2015-07-28 at 14:45 -0700, Andrew Morton wrote: > On Wed, 29 Jul 2015 00:23:18 +0300 Yury wrote: > > > But I think, before/after for x86 is needed as well. > > That would be nice. > > > And why don't you consider '__always_inline__'? Simple inline is only a > > hint and > > guarantees nothing. > > Yup. My x86_64 compiler just ignores the "inline". When I use > __always_inline, find_bit.o's text goes from 776 bytes to 863. > Hopefully we get something in return for that bloat! On my x86_64 (core-i5 something, with disabled cpufreq) i got following numbers: find_next_zero_bit old new __always_inline 20 21 22 20 21 22 20 22 23 21 21 22 21 21 23 20 21 22 20 21 23 21 22 23 20 22 22 21 21 22 find_next_bit old new __always_inline 19 21 24 19 22 24 19 22 24 19 21 24 20 22 24 19 21 23 19 21 23 20 21 24 19 22 24 19 21 24 I will re-check on another machine. It's really interesting if __always_inline makes things better for aarch64 and worse for x86_64. It will be nice if someone will check it on x86_64 too. Best regards, Alexey Klimov. > Also, if _find_next_bit() benefits from this then _find_next_bit_le() > will presumably also benefit. > > -- 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/