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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 4D1E2C282DD for ; Mon, 10 Jun 2019 11:43:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2204F20859 for ; Mon, 10 Jun 2019 11:43:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nRzrOcr2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2204F20859 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=NNQ9vcp93b1L8KI/Nbv5MmWqC1KtEdWUdyZxVJMMTHo=; b=nRzrOcr26IONpl be9Tn4oP8vj08bX2PriW1+Lt4F5f6oBme8J2S2e1JbZJBoo8+75VUDe7VcUVmzCgg+0L4XDR4fTXj aB2n7anq3eAiZZIYGL+7fsroen8V1Cllej2lcl0E8YX7YQHDxVT/QJvnqRYHF9Ud1QXe889MquAuV 2F+3NmHPCw/GpFY9tr2W6TopFB56a26pRZNf/ciF8oL0WEfWa2X8vibMPMknK8edffvJ04RCrz8xR LCPE0zdz6D7v542pdwFVDnM+308ZXPNCIGyr1wG6kUFqIgwClNSisWodVkJJfXndeSg6Cs6iHH2vw Jya4PoUuUigzACfURggQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1haIi5-000687-Ia; Mon, 10 Jun 2019 11:43:33 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1haIi3-00067b-0H for linux-arm-kernel@lists.infradead.org; Mon, 10 Jun 2019 11:43:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7FE98337; Mon, 10 Jun 2019 04:43:30 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C6AD23F557; Mon, 10 Jun 2019 04:45:10 -0700 (PDT) Date: Mon, 10 Jun 2019 12:43:26 +0100 From: Will Deacon To: Mark Rutland Subject: Re: [PATCH -next] arm64/mm: fix a bogus GFP flag in pgd_alloc() Message-ID: <20190610114326.GF15979@fuggles.cambridge.arm.com> References: <1559656836-24940-1-git-send-email-cai@lca.pw> <20190604142338.GC24467@lakrids.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190604142338.GC24467@lakrids.cambridge.arm.com> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190610_044331_088555_BC791972 X-CRM114-Status: GOOD ( 19.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, linux-kernel@vger.kernel.org, mhocko@kernel.org, linux-mm@kvack.org, Qian Cai , vdavydov.dev@gmail.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, akpm@linux-foundation.org, rppt@linux.ibm.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jun 04, 2019 at 03:23:38PM +0100, Mark Rutland wrote: > On Tue, Jun 04, 2019 at 10:00:36AM -0400, Qian Cai wrote: > > The commit "arm64: switch to generic version of pte allocation" > > introduced endless failures during boot like, > > > > kobject_add_internal failed for pgd_cache(285:chronyd.service) (error: > > -2 parent: cgroup) > > > > It turns out __GFP_ACCOUNT is passed to kernel page table allocations > > and then later memcg finds out those don't belong to any cgroup. > > Mike, I understood from [1] that this wasn't expected to be a problem, > as the accounting should bypass kernel threads. > > Was that assumption wrong, or is something different happening here? > > > > > backtrace: > > kobject_add_internal > > kobject_init_and_add > > sysfs_slab_add+0x1a8 > > __kmem_cache_create > > create_cache > > memcg_create_kmem_cache > > memcg_kmem_cache_create_func > > process_one_work > > worker_thread > > kthread > > > > Signed-off-by: Qian Cai > > --- > > arch/arm64/mm/pgd.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c > > index 769516cb6677..53c48f5c8765 100644 > > --- a/arch/arm64/mm/pgd.c > > +++ b/arch/arm64/mm/pgd.c > > @@ -38,7 +38,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm) > > if (PGD_SIZE == PAGE_SIZE) > > return (pgd_t *)__get_free_page(gfp); > > else > > - return kmem_cache_alloc(pgd_cache, gfp); > > + return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_KERNEL); > > This is used to allocate PGDs for both user and kernel pagetables (e.g. > for the efi runtime services), so while this may fix the regression, I'm > not sure it's the right fix. > > Do we need a separate pgd_alloc_kernel()? So can I take the above for -rc5, or is somebody else working on a different fix to implement pgd_alloc_kernel()? /confused Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel