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=-2.7 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 E2539C43334 for ; Tue, 4 Sep 2018 10:47:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B98D2077C for ; Tue, 4 Sep 2018 10:47:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lR4Ayoa8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8B98D2077C 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 S1727321AbeIDPM3 (ORCPT ); Tue, 4 Sep 2018 11:12:29 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:45454 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726208AbeIDPM3 (ORCPT ); Tue, 4 Sep 2018 11:12:29 -0400 Received: by mail-pf1-f195.google.com with SMTP id i26-v6so1490942pfo.12 for ; Tue, 04 Sep 2018 03:47:55 -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=BNS15GySw45MLcrj6NgFJRkc/1V72+qIGsnSMM50p6c=; b=lR4Ayoa8Egf7LcfLET+hKFEJCPY9ST2ocafcSClgn6l8lKLraDjC3U7ceAi1inQfQ2 bpsGz+i3knINtNig38Y8RW2Gr9KKHKko8IA49BEQbt3uXrmSiUb2b2hzVXrt9vy3UOko Rbu3w361pScDKqN8ifW2M+tYX3Lao6Z1VUMot9hrEmP2M56yTMtlbzRyhqyKHUl9QRzZ 3+PY/laKuAgn2vLp8NRukCnJpLJVOMdoSRu/1G8cjdWzYN63E0Z/mK8615t/DfG/TtRj JOfWQk8VwEg3EPFMPvVGoKpe/iSO9M2MbgHfvTItkwZisKRSTChiFlNY/Oe9+a8l4yc0 Wxbg== 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=BNS15GySw45MLcrj6NgFJRkc/1V72+qIGsnSMM50p6c=; b=j0qrOvhmoT7hJF+aUpWE0mB2/VIgSiIpo8Fni7AJHYsocKdxSWFoHC/sBSBOYkeNUk /jbxd2WDWRJkUDx550f0YICw6Kprd6pozRRbJ0PEh/5yzBWXlVewzPJXI9h8KD8HLCyj ZbM1JZeR1aQ+Sw0dwYmj3MrQfhZWNYHuOIZ2iypq9OFUfBVidB2V/kXalqNLSQvg/RO9 2MHZkxusGGPSSCzFK86ofKRVssuMOSl9Dl65NipCCU2t1/uSZOJVVErPMVuLohWtntPe NptQrQWzt0uhH6YTiQ0TTYPv4Y5j4sI5hg+RI7J4VL6Albf7nGO0EGgGgVhRxBorc2VF JKAQ== X-Gm-Message-State: APzg51DhBiFWvnHeZlrYDD8/zJRBfh2/I+BcCsBpPOyGoTf2+YrdDIaq tqemT12QNnB8u+ffMBhButk= X-Google-Smtp-Source: ANB0VdYzYQwdTWVWI6EjIXXnKwmyr300PU2WWYYdR3guvGGe0fj2mfgFa74dkAA39tmgBuESYY2vFg== X-Received: by 2002:a63:a51c:: with SMTP id n28-v6mr366243pgf.453.1536058075480; Tue, 04 Sep 2018 03:47:55 -0700 (PDT) Received: from localhost.localdomain ([45.56.155.158]) by smtp.gmail.com with ESMTPSA id d6-v6sm27917315pgt.66.2018.09.04.03.47.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Sep 2018 03:47:54 -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 v2] libnvdimm, region_devs: stop NDD_ALIASING bit test if one test pass Date: Tue, 4 Sep 2018 06:47:42 -0400 Message-Id: <1536058062-18894-1-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. So it's safe to return ND_DEVICE_NAMESPACE_PMEM if the NDD_ALIASING bit is found inside the loop, while saving a few cpu cycles. Signed-off-by: Ocean He --- v1: https://lkml.org/lkml/2018/8/19/4 v2: Per Vishal's comments in patch v1, remove 'alias' variable. In the loop, just return ND_DEVICE_NAMESPACE_PMEM if the NDD_ALIASING bit is found for any mapping. Outside the loop, simply return ND_DEVICE_NAMESPACE_IO. The following test pass on Lenovo ThinkSystem SR630 based on 4.19-rc1. # ndctl create-namespace -r region0 -s 1g -t pmem -m fsdax # ndctl create-namespace -r region0 -s 1g -t pmem -m sector # ndctl create-namespace -r region0 -s 1g -t pmem -m devdax # ndctl list [ { "dev":"namespace0.2", "mode":"devdax", "map":"dev", "size":1054867456, "uuid":"fc3a2126-9b8e-4ab4-baa4-a3ec7f62a326", "raw_uuid":"eadc6965-daee-48c5-a0ae-1865ee0c8573", "chardev":"dax0.2", "numa_node":0 }, { "dev":"namespace0.1", "mode":"sector", "size":1071616000, "uuid":"0d81d040-93a1-45c6-9791-3dbb7b5f89d2", "raw_uuid":"2b1b29e6-0510-4dcf-9902-43b77ccb9df5", "sector_size":4096, "blockdev":"pmem0.1s", "numa_node":0 }, { "dev":"namespace0.0", "mode":"fsdax", "map":"dev", "size":1054867456, "uuid":"cbff92ed-cd45-4d24-9353-7a56d42122b1", "raw_uuid":"f6ea1001-5ef0-4942-889a-99005079ab5d", "sector_size":512, "blockdev":"pmem0", "numa_node":0 } ] # reboot and OS could boot up normally # ndctl destroy-namespace namespace0.2 -f # ndctl destroy-namespace namespace0.1 -f # ndctl destroy-namespace namespace0.0 -f drivers/nvdimm/region_devs.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index fa37afc..16ee153 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -228,19 +228,18 @@ void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data) int nd_region_to_nstype(struct nd_region *nd_region) { if (is_memory(&nd_region->dev)) { - u16 i, alias; + u16 i; - for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) { + for (i = 0; i < nd_region->ndr_mappings; i++) { struct nd_mapping *nd_mapping = &nd_region->mapping[i]; struct nvdimm *nvdimm = nd_mapping->nvdimm; if (test_bit(NDD_ALIASING, &nvdimm->flags)) - alias++; + return ND_DEVICE_NAMESPACE_PMEM; } - if (alias) - return ND_DEVICE_NAMESPACE_PMEM; - else - return ND_DEVICE_NAMESPACE_IO; + + return ND_DEVICE_NAMESPACE_IO; + } else if (is_nd_blk(&nd_region->dev)) { return ND_DEVICE_NAMESPACE_BLK; } -- 1.8.3.1