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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 00946C43331 for ; Mon, 30 Mar 2020 12:37:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7A6C206F6 for ; Mon, 30 Mar 2020 12:37:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TjkZfDHh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730337AbgC3Mhu (ORCPT ); Mon, 30 Mar 2020 08:37:50 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:38300 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730212AbgC3MhN (ORCPT ); Mon, 30 Mar 2020 08:37:13 -0400 Received: by mail-wr1-f65.google.com with SMTP id s1so21397544wrv.5; Mon, 30 Mar 2020 05:37:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=+5h5Vnp00pGHAWFpA0rxHse7kQHumkG3UT/lUs7Gqbk=; b=TjkZfDHhe89sx/aPLzWq0sDiRtZZyhlNFb25tEjcfJtlLxqgtLrNaMwhI31AaYe+Do aIfkPxyO48Ms+L4rC89nYVLiqnsGU66cVVUJoilDRRAEF2v0F8/3gdUkTRXRbLYfp5oD 6k4K5JM+qtiajl40O2YHwHVUMFfoTjY2ECDiSc2zM4UNSboQmDSPlUJbFVNypMAkUSEg Mz2p7v/x4dlsG2iOw0MPi/JcXR+ss9hQLmQJWEW/kQ6dhGaHO8Ae4YSsLZEd71SpNqA8 xKdFk6fnmIuFw4aUSJUwtwdX0UQBY5UylAWfub7MnN3ogmsez8VR3CcBG+HL+SJTbsI8 fOLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=+5h5Vnp00pGHAWFpA0rxHse7kQHumkG3UT/lUs7Gqbk=; b=moPziA25J8HCHOBxC3CBXHZX1mC6IgENrZ/9iRV4puOVlzCERXGpc/fVoi+EWO+1pM 6zBnWq4UQ1C0AgpDFI3/9Bz/uWh3RUn1F8DOPnOXNPnrvVC6iz3GbFYhoRh6a6i5txFQ /kd2PPcOWLB5l0k9Hwj+iOjI1LGHMnNPrMyjWmx/MtJCIKP2leJAUz0HaXC6SvZI7461 J0NNNq/hokNRMzJ2Ke7facZpP04quUvP4ATMrdfzUroiTr1gxX5h7Qr2jqdYo8ChVwXU xGPh40orGxhHVcZUM6Y7fs9oQXubvstEzRzb0kSTSHZ1+9ubqnUXK8AYEgB2jxOIw03Q +ETA== X-Gm-Message-State: ANhLgQ0pmLp183RsaN33R53ThYy/owD2t4wWsyX5viU4iVceY55CSPtH Ne6jL/cz6M10TNMt0msJ6XWyu32v X-Google-Smtp-Source: ADFU+vvLM4vRWPckeHGmsFeliBH3sfO9hRwleuvO4KwtgKyFi3cmgAx5JHgioT53pz+XP6AVkcAcmQ== X-Received: by 2002:a5d:53c8:: with SMTP id a8mr14345313wrw.242.1585571831552; Mon, 30 Mar 2020 05:37:11 -0700 (PDT) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id c18sm22239966wrx.5.2020.03.30.05.37.10 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 30 Mar 2020 05:37:11 -0700 (PDT) From: Wei Yang To: willy@infradead.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Wei Yang Subject: [PATCH 2/9] XArray: simplify the calculation of shift Date: Mon, 30 Mar 2020 12:36:36 +0000 Message-Id: <20200330123643.17120-3-richard.weiyang@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200330123643.17120-1-richard.weiyang@gmail.com> References: <20200330123643.17120-1-richard.weiyang@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When head is NULL, shift is calculated from max. Currently we use a loop to detect how many XA_CHUNK_SHIFT is need to cover max. To achieve this, we can get number of bits max expands and round it up to XA_CHUNK_SHIFT. Signed-off-by: Wei Yang --- lib/xarray.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/lib/xarray.c b/lib/xarray.c index 1d9fab7db8da..6454cf3f5b4c 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -560,11 +560,7 @@ static int xas_expand(struct xa_state *xas, void *head) unsigned long max = xas_max(xas); if (!head) { - if (max == 0) - return 0; - while ((max >> shift) >= XA_CHUNK_SIZE) - shift += XA_CHUNK_SHIFT; - return shift + XA_CHUNK_SHIFT; + return roundup(fls_long(max), XA_CHUNK_SHIFT); } else if (xa_is_node(head)) { node = xa_to_node(head); shift = node->shift + XA_CHUNK_SHIFT; -- 2.23.0