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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 41F9CC4321D for ; Sun, 19 Aug 2018 04:01:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A85D52170B for ; Sun, 19 Aug 2018 04:01:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PVUA79Ht" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A85D52170B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726031AbeHSHLo (ORCPT ); Sun, 19 Aug 2018 03:11:44 -0400 Received: from mail-qt0-f194.google.com ([209.85.216.194]:37950 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725812AbeHSHLo (ORCPT ); Sun, 19 Aug 2018 03:11:44 -0400 Received: by mail-qt0-f194.google.com with SMTP id x7-v6so3656491qtk.5 for ; Sat, 18 Aug 2018 21:01:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=5D4YUF+p0alJRPnlxV77AWTJkir6fdQLSR8NBHJS0X4=; b=PVUA79HtoOEBHBuPCziHD/XF9UX3ZpJ3vaV9h+OUl+z5lM8uwrmWSgNNcsKHPouDPC v5GxFyHrruLlumfrc2dZNMggTRhxqIQZPFcLbRAWdEVqxg8nlS7YWsVEiM6Bb2raSCUT c5iMbmLUIW9tlbL10hDi0MejLlpsNu5nnG+SnbD8zpiTR9ugBNvNK+hRzMEViC8sFoMH LawWa9h8lziDqEIJHsfs6PudZ7XSmz8yoAwi/GYu79ZDsnruKTgJTC9DgZWg1LKaZ6uq X2Gwj6ausy+mhqUXrb8TyuRnuaPpH5aT6+Qe9KL1GiDqLfpQg4+7rYMs+GUMc16Fia54 v16w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=5D4YUF+p0alJRPnlxV77AWTJkir6fdQLSR8NBHJS0X4=; b=U+E9lchX+TIzpuL80xCsQW8V1zj0NEeLQoQbuystyojhcqDNLSPbJ0+MOPm9Xu60qU zZRKtSE7DfuV5+UAuBRymJ3QgLmTeznkUyiDmXxlkUUdRiWIdiNiQcAtR5CgKXprTmLZ aRZnBkAL/8JCZnBkO1+ZrmE5/4fnclfz34p4bjVcxVte6p+zSXAqUNikUbn3G8OA8puA DIW82RW5L+G+ExJ6bZ4wGOh+BFeH22Eo1eZ78bHHkbtqZIKk/abTq7jSewhKs4+jsnGM W4uc5E6VcXkk+k7nzg5AkeMnVWHqMzJuFW1dTIoP8/CfqmYwwG7xpdq0kRZAHL0sntmD 4zPw== X-Gm-Message-State: AOUpUlGO+98dEoj0eF4nvqI9X3FAblnb0uLVgDsWsZ9DwQddsTx7rK37 fBNaTkNalwnVoWXbYO6atutA4f1OHfM= X-Google-Smtp-Source: AA+uWPy4v3qyWdV/lqnoRf4PnwCFCETwkhjLVfcO8HuJq2vXfnISdurB98EAimeSMz3RMzz08yH+Fg== X-Received: by 2002:a0c:a162:: with SMTP id d89-v6mr36671744qva.198.1534651299429; Sat, 18 Aug 2018 21:01:39 -0700 (PDT) Received: from 192.168.190.131 ([104.237.86.149]) by smtp.gmail.com with ESMTPSA id n186-v6sm3353894qkb.32.2018.08.18.21.01.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 18 Aug 2018 21:01:38 -0700 (PDT) From: Ocean He To: dan.j.williams@intel.com, ross.zwisler@linux.intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, Ocean He Subject: [PATCH] libnvdimm, region_devs: stop NDD_ALIASING bit test if one test pass Date: Sun, 19 Aug 2018 00:01:28 -0400 Message-Id: <1534651288-30306-1-git-send-email-oceanhehy@gmail.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ocean He There is no need to finish entire loop to execute NDD_ALIASING bit test against every nvdimm->flags. In practice, all the nd_mapping->nvdimm have the same flags. Because the check of alias is "if (alias)" but not "if (alias == nd_region->ndr_mappings)", there is no function change while just save a few cycles. Signed-off-by: Ocean He --- A test to check if all the nd_mapping->nvdimm have the same flags, using Lenovo ThinkSystem SR630 and 4.18-rc6. # ipmctl show -dimm DimmID Capacity HealthState ActionRequired LockState FWVersion 0x0021 125.7 GiB Healthy 0 Disabled 01.00.00.4888 0x0121 125.7 GiB Healthy 0 Disabled 01.00.00.4888 0x1021 125.7 GiB Healthy 0 Disabled 01.00.00.4888 0x1121 125.7 GiB Healthy 0 Disabled 01.00.00.4888 # ipmctl create -f -goal -socket 0x0 PersistentMemoryType=AppDirect # ipmctl create -f -goal -socket 0x1 PersistentMemoryType=AppDirect # reboot, to make goal configuration take effect. # ndctl create-namespace -r region0 -s 100m -t pmem -m fsdax # ndctl create-namespace -r region1 -s 100m -t pmem -m fsdax # reboot and find all the nd_mapping->nvdimm have the same flags. drivers/nvdimm/region_devs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index ec3543b..fc3bc1c 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -234,8 +234,10 @@ int nd_region_to_nstype(struct nd_region *nd_region) struct nd_mapping *nd_mapping = &nd_region->mapping[i]; struct nvdimm *nvdimm = nd_mapping->nvdimm; - if (test_bit(NDD_ALIASING, &nvdimm->flags)) + if (test_bit(NDD_ALIASING, &nvdimm->flags)) { alias++; + break; + } } if (alias) return ND_DEVICE_NAMESPACE_PMEM; -- 1.8.3.1