From patchwork Fri Jan 22 02:33:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 12038199 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=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 85F5AC433DB for ; Fri, 22 Jan 2021 02:38:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53BC623136 for ; Fri, 22 Jan 2021 02:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726738AbhAVCiF (ORCPT ); Thu, 21 Jan 2021 21:38:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:40057 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726695AbhAVCfg (ORCPT ); Thu, 21 Jan 2021 21:35:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611282850; 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=dz69XAp6V25w6/fUS/AfxO4UWms2LrSSlaFzOyuN0DA=; b=gCVPrVhkUg3vigFR2h7/9ZY+sz8L5TeRnlwlSe8zuY6Ju48gwbiULVEpxKTdt+gbJZ89+6 gh6Gwt2iFijyuTW2T/f6xvSIeDKGXcoDsmVribu3G07+VhbC8xGBtkxbknmAbJfvkLjv64 drELo6QrHpsjsIlwv1J3PHqxOoJWoKk= 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-117-r7fP57pUNPGwzlMzRmA_Mw-1; Thu, 21 Jan 2021 21:34:08 -0500 X-MC-Unique: r7fP57pUNPGwzlMzRmA_Mw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 322A410054FF; Fri, 22 Jan 2021 02:34:07 +0000 (UTC) Received: from localhost (ovpn-13-11.pek2.redhat.com [10.72.13.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 82575100AE44; Fri, 22 Jan 2021 02:34:02 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, "Martin K . Petersen" , linux-scsi@vger.kernel.org Cc: Ming Lei , Omar Sandoval , Kashyap Desai , Sumanesh Samanta , "Ewan D . Milne" , Hannes Reinecke Subject: [PATCH V7 03/13] sbitmap: add helpers for updating allocation hint Date: Fri, 22 Jan 2021 10:33:07 +0800 Message-Id: <20210122023317.687987-4-ming.lei@redhat.com> In-Reply-To: <20210122023317.687987-1-ming.lei@redhat.com> References: <20210122023317.687987-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Add helpers for updating allocation hint, so that we can avoid to duplicate code. Prepare for moving allocation hint into sbitmap. Cc: Omar Sandoval Cc: Kashyap Desai Cc: Sumanesh Samanta Cc: Ewan D. Milne Cc: Hannes Reinecke Reviewed-by: Hannes Reinecke Tested-by: Sumanesh Samanta Signed-off-by: Ming Lei --- lib/sbitmap.c | 93 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 54 insertions(+), 39 deletions(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 7000636933b3..2b43a6aefec3 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -9,6 +9,55 @@ #include #include +static int init_alloc_hint(struct sbitmap_queue *sbq, gfp_t flags) +{ + unsigned depth = sbq->sb.depth; + + sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); + if (!sbq->alloc_hint) + return -ENOMEM; + + if (depth && !sbq->sb.round_robin) { + int i; + + for_each_possible_cpu(i) + *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth; + } + + return 0; +} + +static inline unsigned update_alloc_hint_before_get(struct sbitmap_queue *sbq, + unsigned int depth) +{ + unsigned hint; + + hint = this_cpu_read(*sbq->alloc_hint); + if (unlikely(hint >= depth)) { + hint = depth ? prandom_u32() % depth : 0; + this_cpu_write(*sbq->alloc_hint, hint); + } + + return hint; +} + +static inline void update_alloc_hint_after_get(struct sbitmap_queue *sbq, + unsigned int depth, + unsigned int hint, + unsigned int nr) +{ + if (nr == -1) { + /* If the map is full, a hint won't do us much good. */ + this_cpu_write(*sbq->alloc_hint, 0); + } else if (nr == hint || unlikely(sbq->sb.round_robin)) { + /* Only update the hint if we used it. */ + hint = nr + 1; + if (hint >= depth - 1) + hint = 0; + this_cpu_write(*sbq->alloc_hint, hint); + } +} + /* * See if we have deferred clears that we can batch move */ @@ -355,17 +404,11 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, if (ret) return ret; - sbq->alloc_hint = alloc_percpu_gfp(unsigned int, flags); - if (!sbq->alloc_hint) { + if (init_alloc_hint(sbq, flags) != 0) { sbitmap_free(&sbq->sb); return -ENOMEM; } - if (depth && !round_robin) { - for_each_possible_cpu(i) - *per_cpu_ptr(sbq->alloc_hint, i) = prandom_u32() % depth; - } - sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); @@ -418,24 +461,10 @@ int __sbitmap_queue_get(struct sbitmap_queue *sbq) unsigned int hint, depth; int nr; - hint = this_cpu_read(*sbq->alloc_hint); depth = READ_ONCE(sbq->sb.depth); - if (unlikely(hint >= depth)) { - hint = depth ? prandom_u32() % depth : 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + hint = update_alloc_hint_before_get(sbq, depth); nr = sbitmap_get(&sbq->sb, hint); - - if (nr == -1) { - /* If the map is full, a hint won't do us much good. */ - this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->sb.round_robin)) { - /* Only update the hint if we used it. */ - hint = nr + 1; - if (hint >= depth - 1) - hint = 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + update_alloc_hint_after_get(sbq, depth, hint, nr); return nr; } @@ -449,24 +478,10 @@ int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); - hint = this_cpu_read(*sbq->alloc_hint); depth = READ_ONCE(sbq->sb.depth); - if (unlikely(hint >= depth)) { - hint = depth ? prandom_u32() % depth : 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + hint = update_alloc_hint_before_get(sbq, depth); nr = sbitmap_get_shallow(&sbq->sb, hint, shallow_depth); - - if (nr == -1) { - /* If the map is full, a hint won't do us much good. */ - this_cpu_write(*sbq->alloc_hint, 0); - } else if (nr == hint || unlikely(sbq->sb.round_robin)) { - /* Only update the hint if we used it. */ - hint = nr + 1; - if (hint >= depth - 1) - hint = 0; - this_cpu_write(*sbq->alloc_hint, hint); - } + update_alloc_hint_after_get(sbq, depth, hint, nr); return nr; }