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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 D8D1DC433FF for ; Tue, 30 Jul 2019 22:54:27 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5007E205C9 for ; Tue, 30 Jul 2019 22:54:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5007E205C9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45ysLn0SCQzDqYk for ; Wed, 31 Jul 2019 08:54:25 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45ysFx4D9JzDqLc for ; Wed, 31 Jul 2019 08:50:13 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 45ysFw05hKz9sMQ; Wed, 31 Jul 2019 08:50:11 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: da1115fdbd6e86c62185cdd2b4bf7add39f2f82b In-Reply-To: <20190729095128.23707-1-aneesh.kumar@linux.ibm.com> To: "Aneesh Kumar K.V" , npiggin@gmail.com, paulus@samba.org, "Oliver O'Halloran" From: Michael Ellerman Subject: Re: [PATCH v3] powerpc/nvdimm: Pick nearby online node if the device node is not online Message-Id: <45ysFw05hKz9sMQ@ozlabs.org> Date: Wed, 31 Jul 2019 08:50:11 +1000 (AEST) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Aneesh Kumar K.V" , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, 2019-07-29 at 09:51:28 UTC, "Aneesh Kumar K.V" wrote: > Currently, nvdimm subsystem expects the device numa node for SCM device to be > an online node. It also doesn't try to bring the device numa node online. Hence > if we use a non-online numa node as device node we hit crashes like below. This > is because we try to access uninitialized NODE_DATA in different code paths. > > cpu 0x0: Vector: 300 (Data Access) at [c0000000fac53170] > pc: c0000000004bbc50: ___slab_alloc+0x120/0xca0 > lr: c0000000004bc834: __slab_alloc+0x64/0xc0 > sp: c0000000fac53400 > msr: 8000000002009033 > dar: 73e8 > dsisr: 80000 > current = 0xc0000000fabb6d80 > paca = 0xc000000003870000 irqmask: 0x03 irq_happened: 0x01 > pid = 7, comm = kworker/u16:0 > Linux version 5.2.0-06234-g76bd729b2644 (kvaneesh@ltc-boston123) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #135 SMP Thu Jul 11 05:36:30 CDT 2019 > enter ? for help > [link register ] c0000000004bc834 __slab_alloc+0x64/0xc0 > [c0000000fac53400] c0000000fac53480 (unreliable) > [c0000000fac53500] c0000000004bc818 __slab_alloc+0x48/0xc0 > [c0000000fac53560] c0000000004c30a0 __kmalloc_node_track_caller+0x3c0/0x6b0 > [c0000000fac535d0] c000000000cfafe4 devm_kmalloc+0x74/0xc0 > [c0000000fac53600] c000000000d69434 nd_region_activate+0x144/0x560 > [c0000000fac536d0] c000000000d6b19c nd_region_probe+0x17c/0x370 > [c0000000fac537b0] c000000000d6349c nvdimm_bus_probe+0x10c/0x230 > [c0000000fac53840] c000000000cf3cc4 really_probe+0x254/0x4e0 > [c0000000fac538d0] c000000000cf429c driver_probe_device+0x16c/0x1e0 > [c0000000fac53950] c000000000cf0b44 bus_for_each_drv+0x94/0x130 > [c0000000fac539b0] c000000000cf392c __device_attach+0xdc/0x200 > [c0000000fac53a50] c000000000cf231c bus_probe_device+0x4c/0xf0 > [c0000000fac53a90] c000000000ced268 device_add+0x528/0x810 > [c0000000fac53b60] c000000000d62a58 nd_async_device_register+0x28/0xa0 > [c0000000fac53bd0] c0000000001ccb8c async_run_entry_fn+0xcc/0x1f0 > [c0000000fac53c50] c0000000001bcd9c process_one_work+0x46c/0x860 > [c0000000fac53d20] c0000000001bd4f4 worker_thread+0x364/0x5f0 > [c0000000fac53db0] c0000000001c7260 kthread+0x1b0/0x1c0 > [c0000000fac53e20] c00000000000b954 ret_from_kernel_thread+0x5c/0x68 > > The patch tries to fix this by picking the nearest online node as the SCM node. > This does have a problem of us losing the information that SCM node is > equidistant from two other online nodes. If applications need to understand these > fine-grained details we should express then like x86 does via > /sys/devices/system/node/nodeX/accessY/initiators/ > > With the patch we get > > # numactl -H > available: 2 nodes (0-1) > node 0 cpus: > node 0 size: 0 MB > node 0 free: 0 MB > node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 > node 1 size: 130865 MB > node 1 free: 129130 MB > node distances: > node 0 1 > 0: 10 20 > 1: 20 10 > # cat /sys/bus/nd/devices/region0/numa_node > 0 > # dmesg | grep papr_scm > [ 91.332305] papr_scm ibm,persistent-memory:ibm,pmemory@44104001: Region registered with target node 2 and online node 0 > > Signed-off-by: Aneesh Kumar K.V Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/da1115fdbd6e86c62185cdd2b4bf7add39f2f82b cheers