From patchwork Mon Jul 28 21:47:41 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mikulas Patocka X-Patchwork-Id: 4637661 X-Patchwork-Delegate: snitzer@redhat.com Return-Path: X-Original-To: patchwork-dm-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9F1D59F38C for ; Mon, 28 Jul 2014 21:53:23 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DCC0E20173 for ; Mon, 28 Jul 2014 21:53:22 +0000 (UTC) Received: from mx3-phx2.redhat.com (mx3-phx2.redhat.com [209.132.183.24]) by mail.kernel.org (Postfix) with ESMTP id 074C62015D for ; Mon, 28 Jul 2014 21:53:21 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by mx3-phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s6SLlgSQ024167; Mon, 28 Jul 2014 17:47:43 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s6SLlg8t029786 for ; Mon, 28 Jul 2014 17:47:42 -0400 Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s6SLlfvL018439 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 28 Jul 2014 17:47:41 -0400 Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id s6SLlflk029372; Mon, 28 Jul 2014 17:47:41 -0400 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id s6SLlfCq029368; Mon, 28 Jul 2014 17:47:41 -0400 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Mon, 28 Jul 2014 17:47:41 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Mike Snitzer , "Alasdair G. Kergon" , dm-devel@redhat.com In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-loop: dm-devel@redhat.com Cc: Jay Wang Subject: [dm-devel] [PATCH 1/2] dm-switch: quickly load repetitive pattern X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP dm-switch: introdice switch_region_table_read Move a code that reads the table to a separate function. It will be needed for the next patch. Signed-off-by: Mikulas Patocka --- drivers/md/dm-switch.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel Index: linux-3.15/drivers/md/dm-switch.c =================================================================== --- linux-3.15.orig/drivers/md/dm-switch.c 2014-06-26 22:25:10.000000000 +0200 +++ linux-3.15/drivers/md/dm-switch.c 2014-06-27 14:08:06.000000000 +0200 @@ -137,13 +137,23 @@ static void switch_get_position(struct s *bit *= sctx->region_table_entry_bits; } +static unsigned switch_region_table_read(struct switch_ctx *sctx, unsigned long region_nr) +{ + unsigned long region_index; + unsigned bit; + + switch_get_position(sctx, region_nr, ®ion_index, &bit); + + return (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) & + ((1 << sctx->region_table_entry_bits) - 1); +} + /* * Find which path to use at given offset. */ static unsigned switch_get_path_nr(struct switch_ctx *sctx, sector_t offset) { - unsigned long region_index; - unsigned bit, path_nr; + unsigned path_nr; sector_t p; p = offset; @@ -152,9 +162,7 @@ static unsigned switch_get_path_nr(struc else sector_div(p, sctx->region_size); - switch_get_position(sctx, p, ®ion_index, &bit); - path_nr = (ACCESS_ONCE(sctx->region_table[region_index]) >> bit) & - ((1 << sctx->region_table_entry_bits) - 1); + path_nr = switch_region_table_read(sctx, p); /* This can only happen if the processor uses non-atomic stores. */ if (unlikely(path_nr >= sctx->nr_paths))