From patchwork Thu Oct 12 18:37:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10002505 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 414B660216 for ; Thu, 12 Oct 2017 18:38:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 363BE28E6F for ; Thu, 12 Oct 2017 18:38:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2AC1A28E75; Thu, 12 Oct 2017 18:38:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ABDFF28E6F for ; Thu, 12 Oct 2017 18:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751925AbdJLSiV (ORCPT ); Thu, 12 Oct 2017 14:38:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37356 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751373AbdJLSiR (ORCPT ); Thu, 12 Oct 2017 14:38:17 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0C0252CE969; Thu, 12 Oct 2017 18:38:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0C0252CE969 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=ming.lei@redhat.com Received: from localhost (ovpn-12-77.pek2.redhat.com [10.72.12.77]) by smtp.corp.redhat.com (Postfix) with ESMTP id D01975D9CC; Thu, 12 Oct 2017 18:38:01 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig Cc: Bart Van Assche , Laurence Oberman , Paolo Valente , Oleksandr Natalenko , Tom Nguyen , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Omar Sandoval , John Garry , Ming Lei Subject: [PATCH V7 3/6] sbitmap: introduce __sbitmap_for_each_set() Date: Fri, 13 Oct 2017 02:37:01 +0800 Message-Id: <20171012183704.22326-4-ming.lei@redhat.com> In-Reply-To: <20171012183704.22326-1-ming.lei@redhat.com> References: <20171012183704.22326-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 12 Oct 2017 18:38:17 +0000 (UTC) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We need to iterate ctx starting from any ctx in round robin way, so introduce this helper. Reviewed-by: Omar Sandoval Cc: Omar Sandoval Signed-off-by: Ming Lei --- include/linux/sbitmap.h | 64 ++++++++++++++++++++++++++++++++++++------------- 1 file changed, 47 insertions(+), 17 deletions(-) diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index a1904aadbc45..0dcc60e820de 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -211,10 +211,14 @@ bool sbitmap_any_bit_set(const struct sbitmap *sb); */ bool sbitmap_any_bit_clear(const struct sbitmap *sb); +#define SB_NR_TO_INDEX(sb, bitnr) ((bitnr) >> (sb)->shift) +#define SB_NR_TO_BIT(sb, bitnr) ((bitnr) & ((1U << (sb)->shift) - 1U)) + typedef bool (*sb_for_each_fn)(struct sbitmap *, unsigned int, void *); /** - * sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap. + * __sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap. + * @start: Where to start the iteration. * @sb: Bitmap to iterate over. * @fn: Callback. Should return true to continue or false to break early. * @data: Pointer to pass to callback. @@ -222,35 +226,61 @@ typedef bool (*sb_for_each_fn)(struct sbitmap *, unsigned int, void *); * This is inline even though it's non-trivial so that the function calls to the * callback will hopefully get optimized away. */ -static inline void sbitmap_for_each_set(struct sbitmap *sb, sb_for_each_fn fn, - void *data) +static inline void __sbitmap_for_each_set(struct sbitmap *sb, + unsigned int start, + sb_for_each_fn fn, void *data) { - unsigned int i; + unsigned int index; + unsigned int nr; + unsigned int scanned = 0; - for (i = 0; i < sb->map_nr; i++) { - struct sbitmap_word *word = &sb->map[i]; - unsigned int off, nr; + if (start >= sb->depth) + start = 0; + index = SB_NR_TO_INDEX(sb, start); + nr = SB_NR_TO_BIT(sb, start); - if (!word->word) - continue; + while (scanned < sb->depth) { + struct sbitmap_word *word = &sb->map[index]; + unsigned int depth = min_t(unsigned int, word->depth - nr, + sb->depth - scanned); - nr = 0; - off = i << sb->shift; + scanned += depth; + if (!word->word) + goto next; + + /* + * On the first iteration of the outer loop, we need to add the + * bit offset back to the size of the word for find_next_bit(). + * On all other iterations, nr is zero, so this is a noop. + */ + depth += nr; while (1) { - nr = find_next_bit(&word->word, word->depth, nr); - if (nr >= word->depth) + nr = find_next_bit(&word->word, depth, nr); + if (nr >= depth) break; - - if (!fn(sb, off + nr, data)) + if (!fn(sb, (index << sb->shift) + nr, data)) return; nr++; } +next: + nr = 0; + if (++index >= sb->map_nr) + index = 0; } } -#define SB_NR_TO_INDEX(sb, bitnr) ((bitnr) >> (sb)->shift) -#define SB_NR_TO_BIT(sb, bitnr) ((bitnr) & ((1U << (sb)->shift) - 1U)) +/** + * sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap. + * @sb: Bitmap to iterate over. + * @fn: Callback. Should return true to continue or false to break early. + * @data: Pointer to pass to callback. + */ +static inline void sbitmap_for_each_set(struct sbitmap *sb, sb_for_each_fn fn, + void *data) +{ + __sbitmap_for_each_set(sb, 0, fn, data); +} static inline unsigned long *__sbitmap_word(struct sbitmap *sb, unsigned int bitnr)