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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 DF0BDC352A3 for ; Tue, 11 Feb 2020 12:12:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7344206DB for ; Tue, 11 Feb 2020 12:12:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WC60ixEL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728617AbgBKMMo (ORCPT ); Tue, 11 Feb 2020 07:12:44 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:35375 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728241AbgBKMMo (ORCPT ); Tue, 11 Feb 2020 07:12:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581423163; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dNMWdKtvi6Hy1HcK6nwSHcXHEGZv8eiC4BgPrfgPvCs=; b=WC60ixELY2afW7eBNbdSahCqpIw+172sr2W4EC1CWiLbDNa225m0plTqwypJXIYyLhGfRS 5G2BmVXJQI/4iHyc8CIKqUgf8H05CrJ8aDYM6Sl1YJ9ZB8ILzukm39RVkr2vri7BPFTX7y KgagMDSBwiaIZSVcr5PBQKQtHA9fM7U= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-282-FvDEbcXYMJOGcg5pLV9TGg-1; Tue, 11 Feb 2020 07:12:39 -0500 X-MC-Unique: FvDEbcXYMJOGcg5pLV9TGg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AD58F8014CA; Tue, 11 Feb 2020 12:12:37 +0000 (UTC) Received: from localhost (ovpn-8-17.pek2.redhat.com [10.72.8.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id E9EE98B548; Tue, 11 Feb 2020 12:12:30 +0000 (UTC) From: Ming Lei To: James Bottomley , linux-scsi@vger.kernel.org, "Martin K . Petersen" , linux-block@vger.kernel.org, Jens Axboe Cc: Ming Lei , Omar Sandoval , Sathya Prakash , Chaitra P B , Suganath Prabu Subramani , Kashyap Desai , Sumit Saxena , Shivasharan S , "Ewan D . Milne" , Hannes Reinecke , Bart Van Assche Subject: [PATCH 06/10] sbitmap: add helper of sbitmap_calculate_shift Date: Tue, 11 Feb 2020 20:11:31 +0800 Message-Id: <20200211121135.30064-7-ming.lei@redhat.com> In-Reply-To: <20200211121135.30064-1-ming.lei@redhat.com> References: <20200211121135.30064-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Content-Transfer-Encoding: quoted-printable Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Move code for calculating default shift into one public helper, which can be used for SCSI to calculate shift. Cc: Omar Sandoval Cc: Sathya Prakash Cc: Chaitra P B Cc: Suganath Prabu Subramani Cc: Kashyap Desai Cc: Sumit Saxena Cc: Shivasharan S Cc: Ewan D. Milne Cc: Hannes Reinecke Cc: Bart Van Assche Signed-off-by: Ming Lei --- include/linux/sbitmap.h | 18 ++++++++++++++++++ lib/sbitmap.c | 16 +++------------- 2 files changed, 21 insertions(+), 13 deletions(-) diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 34343ce3ef6c..2a40364d6d00 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -337,6 +337,24 @@ static inline int sbitmap_test_bit(struct sbitmap *s= b, unsigned int bitnr) return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr)); } =20 +static inline int sbitmap_calculate_shift(unsigned int depth) +{ + int shift =3D ilog2(BITS_PER_LONG); + + /* + * If the bitmap is small, shrink the number of bits per word so + * we spread over a few cachelines, at least. If less than 4 + * bits, just forget about it, it's not going to work optimally + * anyway. + */ + if (depth >=3D 4) { + while ((4U << shift) > depth) + shift--; + } + + return shift; +} + /** * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_fi= le. * @sb: Bitmap to show. diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 254475865b3d..bb88a3643d64 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -96,19 +96,9 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int= depth, int shift, unsigned int bits_per_word; unsigned int i; =20 - if (shift < 0) { - shift =3D ilog2(BITS_PER_LONG); - /* - * If the bitmap is small, shrink the number of bits per word so - * we spread over a few cachelines, at least. If less than 4 - * bits, just forget about it, it's not going to work optimally - * anyway. - */ - if (depth >=3D 4) { - while ((4U << shift) > depth) - shift--; - } - } + if (shift < 0) + shift =3D sbitmap_calculate_shift(depth); + bits_per_word =3D 1U << shift; if (bits_per_word > BITS_PER_LONG) return -EINVAL; --=20 2.20.1