From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8BEEC3A5A0 for ; Thu, 22 Aug 2019 01:25:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8063622CE3 for ; Thu, 22 Aug 2019 01:25:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566437113; bh=fAmchYbKEVyEzsyvePBupZlerJN00M59W8q92U6VFWE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=IkgvpE1Aa0tbdK3UiezC6RChXSVhklq7k0dZ96tlwuGgD3VSY+ZQgTkIciurGDxTr H+pDmsKXwq/PGnj2KxY5qSBvPr645dlFVR6m+l6pLCHA3LIRw5zuf/7F8iTqQihmxD 733ejg8mAiFe/eoqtfl9WNsz4rbmJBz0tQnZyfDw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730347AbfHVBZJ (ORCPT ); Wed, 21 Aug 2019 21:25:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:57700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727316AbfHVBZJ (ORCPT ); Wed, 21 Aug 2019 21:25:09 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BAEF82070B; Thu, 22 Aug 2019 01:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566437108; bh=fAmchYbKEVyEzsyvePBupZlerJN00M59W8q92U6VFWE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=JLwdMo+hkWLZOEkgdKA7JoF8CUwv8bb3SEouBLk6DfZo3p8jwE/B/YUmbd73PqoP+ pY043x+Frcc6EJOugkUGrR78tacGWuftGkakWA8i4+mYeMXkiiuW6eVbkNLH1We1iR zmiIgwJwszIRadhGE56IP6mnlCmzfKY7o3pfKh90= Date: Wed, 21 Aug 2019 18:25:07 -0700 From: Andrew Morton To: Denis Efremov Cc: Akinobu Mita , Jan Kara , Matthew Wilcox , linux-kernel@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org, linux-media@vger.kernel.org, Erdem Tumurov , Vladimir Shelekhov Subject: Re: [PATCH] lib/memweight.c: optimize by inlining bitmap_weight() Message-Id: <20190821182507.b0dea16f57360cf0ac40deb6@linux-foundation.org> In-Reply-To: <20190821074200.2203-1-efremov@ispras.ru> References: <20190821074200.2203-1-efremov@ispras.ru> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, 21 Aug 2019 10:42:00 +0300 Denis Efremov wrote: > This patch inlines bitmap_weight() call. It is better to say the patch "open codes" the bitmap_weight() call. > Thus, removing the BUG_ON, Why is that OK to do? I expect all the code size improvements are from doing this? > and 'longs to bits -> bits to longs' conversion by directly calling > hweight_long(). > > ./scripts/bloat-o-meter lib/memweight.o.old lib/memweight.o.new > add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-10 (-10) > Function old new delta > memweight 162 152 -10 >