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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D3D0C48BC1 for ; Wed, 14 Feb 2024 12:31:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 12B356B0078; Wed, 14 Feb 2024 07:31:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0DDD06B007B; Wed, 14 Feb 2024 07:31:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EE5396B0089; Wed, 14 Feb 2024 07:31:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id DB8E66B0078 for ; Wed, 14 Feb 2024 07:31:50 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 787A2A05FB for ; Wed, 14 Feb 2024 12:31:50 +0000 (UTC) X-FDA: 81790345980.24.C389F6E Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf23.hostedemail.com (Postfix) with ESMTP id 7147914001E for ; Wed, 14 Feb 2024 12:31:48 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=VDOvKLUb; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf23.hostedemail.com: domain of pauld@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=pauld@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1707913908; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=D9vLY8T3+KMronmH2QmMJQBkacfjmZkBy5ra1Aycnxw=; b=mZqbC0Elf/oI9uH3Iys4kRK+YLJAcjbMn4ix2OXMEr7iAICjIMRMmv3D3K4+EpGAha1EgU dpNFcYaKl3sFxvmdqHs9cil90VkkD1t678pJnG55mJmOXwfIF6bSLv+/IwP4JoHvhoImvr wc1iqVJ5LvLwFFuS1tcpGuiBR0TEnIY= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=VDOvKLUb; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf23.hostedemail.com: domain of pauld@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=pauld@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1707913908; a=rsa-sha256; cv=none; b=2SeLjPD22v/uWGBJibyIIu9t9BWSv4Oi8xW99bO9JeMClibwgtxNDhkMKU+ah/3RQER+xZ B2HKXkqwibDTAegO/qnE1pHolss6QvQeY7yr99owqtaAOuTJzi0wvSA+cjX3c72dhHCB0u KodjWgKb3lAqw59rS66fHiZqc0GMAao= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707913907; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=D9vLY8T3+KMronmH2QmMJQBkacfjmZkBy5ra1Aycnxw=; b=VDOvKLUbFclZOx/aPgq3ndNKDByeM2y+w4bBo9biP5uPe67lW78pdFWJJhKxjI0A+nLU4I vGMZbECoQsrzdvXVvRomEWA4EAZ9v0uXSEAFjhtL9R2nipvVuDXDT359wxylPPJdCQ9fgp w20LwDVsMi087ZMwssKEu9I1/IpvaX0= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-623-_DKCtM7WNwiKEuQREe1LwA-1; Wed, 14 Feb 2024 07:31:42 -0500 X-MC-Unique: _DKCtM7WNwiKEuQREe1LwA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7BCEF1C05ABC; Wed, 14 Feb 2024 12:31:41 +0000 (UTC) Received: from lorien.usersys.redhat.com (unknown [10.22.16.162]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AA7DDC185C0; Wed, 14 Feb 2024 12:31:38 +0000 (UTC) Date: Wed, 14 Feb 2024 07:31:37 -0500 From: Phil Auld To: Byungchul Park Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.com, akpm@linux-foundation.org Subject: Re: [PATCH] sched/numa, mm: do not promote folios to nodes not set N_MEMORY Message-ID: <20240214123137.GA70927@lorien.usersys.redhat.com> References: <20240214035355.18335-1-byungchul@sk.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240214035355.18335-1-byungchul@sk.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 7147914001E X-Stat-Signature: uoip1t96p99ofj8783a5nwgcho1yc1ga X-HE-Tag: 1707913908-732678 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi, On Wed, Feb 14, 2024 at 12:53:55PM +0900 Byungchul Park wrote: > While running qemu with a configuration where some CPUs don't have their > local memory and with a kernel numa balancing on, the following oops has > been observed. It's because of null pointers of ->zone_pgdat of zones of > those nodes that are not initialized at booting time. So should avoid > nodes not set N_MEMORY from getting promoted. > > > BUG: unable to handle page fault for address: 00000000000033f3 > > #PF: supervisor read access in kernel mode > > #PF: error_code(0x0000) - not-present page > > PGD 0 P4D 0 > > Oops: 0000 [#1] PREEMPT SMP NOPTI > > CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255 > > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > > rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > > RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) > > Code: (omitted) > > RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 > > RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 > > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 > > RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff > > R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 > > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 > > FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > PKRU: 55555554 > > Call Trace: > > > > ? __die > > ? page_fault_oops > > ? __pte_offset_map_lock > > ? exc_page_fault > > ? asm_exc_page_fault > > ? wakeup_kswapd > > migrate_misplaced_page > > __handle_mm_fault > > handle_mm_fault > > do_user_addr_fault > > exc_page_fault > > asm_exc_page_fault > > RIP: 0033:0x55b897ba0808 > > Code: (omitted) > > RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287 > > RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0 > > RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0 > > RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075 > > R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 > > R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000 > > > > Modules linked in: > > CR2: 00000000000033f3 > > ---[ end trace 0000000000000000 ]--- > > RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812) > > Code: (omitted) > > RSP: 0000:ffffc90004257d58 EFLAGS: 00010286 > > RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003 > > RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480 > > RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff > > R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003 > > R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940 > > FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > PKRU: 55555554 > > note: masim[895] exited with irqs disabled I think you could trim the down a little bit. > > Signed-off-by: Byungchul Park > Reported-by: hyeongtak.ji@sk.com > --- > kernel/sched/fair.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index d7a3c63a2171..6d215cc85f14 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -1828,6 +1828,23 @@ bool should_numa_migrate_memory(struct task_struct *p, struct folio *folio, > int dst_nid = cpu_to_node(dst_cpu); > int last_cpupid, this_cpupid; > > + /* > + * A node of dst_nid might not have its local memory. Promoting > + * a folio to the node is meaningless. What's even worse, oops > + * can be observed by the null pointer of ->zone_pgdat in > + * various points of the code during migration. > + * > + * For instance, oops has been observed at CPU2 while qemu'ing: > + * > + * {qemu} \ > + * -numa node,nodeid=0,mem=1G,cpus=0-1 \ > + * -numa node,nodeid=1,cpus=2-3 \ > + * -numa node,nodeid=2,mem=8G \ > + * ... This part above should probably be in the commit message not in the code. The first paragraph of comment is plenty. Otherwise, I think the check probably makes sense. Cheers, Phil > + */ > + if (!node_state(dst_nid, N_MEMORY)) > + return false; > + > /* > * The pages in slow memory node should be migrated according > * to hot/cold instead of private/shared. > -- > 2.17.1 > > --