From patchwork Fri Feb 28 23:29:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 11413483 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B0127159A for ; Fri, 28 Feb 2020 23:29:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F105246A8 for ; Fri, 28 Feb 2020 23:29:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="C+i9ETEO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726603AbgB1X3t (ORCPT ); Fri, 28 Feb 2020 18:29:49 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:42749 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726658AbgB1X3t (ORCPT ); Fri, 28 Feb 2020 18:29:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582932588; 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=Vp58DvZjnpkYaJYd38hCRkXrB4APAd+myF/vlSec9bE=; b=C+i9ETEOECkgbb6EI5OfrwNUid+aAjGCUj11cASlscf81lRdnkYvVGLkzBOckMB5fsxqqh OkU1WupmBCP3WkqVPWpxXxds90exGNHW//9PblXr6rpKWrqgCeQjrAkNPi0Ivn5VVK7UuC s6gRjyeGWDPyAc7dIFU4qRHM0IMLJsE= 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-25-aTwSBZpoO1GBgHiaEdALsA-1; Fri, 28 Feb 2020 18:29:44 -0500 X-MC-Unique: aTwSBZpoO1GBgHiaEdALsA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2BAA18017DF; Fri, 28 Feb 2020 23:29:42 +0000 (UTC) Received: from localhost (ovpn-8-18.pek2.redhat.com [10.72.8.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id B994F19C7F; Fri, 28 Feb 2020 23:29:38 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, James Bottomley , linux-scsi@vger.kernel.org, "Martin K . Petersen" 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 V2 02/10] sbitmap: add helpers for updating allocation hint Date: Sat, 29 Feb 2020 07:29:12 +0800 Message-Id: <20200228232920.20960-3-ming.lei@redhat.com> In-Reply-To: <20200228232920.20960-1-ming.lei@redhat.com> References: <20200228232920.20960-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-block-owner@vger.kernel.org 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: 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 --- lib/sbitmap.c | 93 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 54 insertions(+), 39 deletions(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 86018a6fccae..683343e02c3b 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 */ @@ -360,17 +409,11 @@ 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); @@ -423,24 +466,10 @@ 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; } @@ -454,24 +483,10 @@ 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; }