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=-8.5 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,URIBL_BLOCKED,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 B3665C282CE for ; Tue, 4 Jun 2019 14:23:51 +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 8C5AF243F6 for ; Tue, 4 Jun 2019 14:23:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uyv+ntBb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8C5AF243F6 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=a9ZLnYlf6YoiaxWn5ht/ALklIC5CkAf6XapsagWzOAI=; b=uyv+ntBbEzqo/9 Ua3gsX8XlKCP+892/PC/f6x6eI2GRT9ec8HrVjNtaQ3U+0NJaRSYo+HNr7eQsBh0qSC6boe/QBUJy SOnofnZJ19JhtJ+XSoVAnRqpPaLs4d+ffWLK5/cMuFe0XNy6lBEq2YGi0CU3OyF3tkfklIDs+VnyG 0LpmJgOBTOnNfzFN84hRggTyosuegUugXEhChSd2hNIvxuS2eMI1O2yeugQkdh8/hIH0AAZH22qhn zwpYrdEJ4sf+716G1KrU5xd1c2Jg5C4m3x3FW3GFI8SX/OrNDhwxr+EimiQdeyFXHbU/Aiw2VZF6s dUlihopP7LoX2ypoddmQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYALs-00041f-Fv; Tue, 04 Jun 2019 14:23:48 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYALp-000411-RD for linux-arm-kernel@lists.infradead.org; Tue, 04 Jun 2019 14:23:47 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0E423341; Tue, 4 Jun 2019 07:23:43 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EDBD23F690; Tue, 4 Jun 2019 07:23:40 -0700 (PDT) Date: Tue, 4 Jun 2019 15:23:38 +0100 From: Mark Rutland To: Qian Cai , rppt@linux.ibm.com Subject: Re: [PATCH -next] arm64/mm: fix a bogus GFP flag in pgd_alloc() Message-ID: <20190604142338.GC24467@lakrids.cambridge.arm.com> References: <1559656836-24940-1-git-send-email-cai@lca.pw> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1559656836-24940-1-git-send-email-cai@lca.pw> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190604_072345_888914_11FD3600 X-CRM114-Status: GOOD ( 17.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, mhocko@kernel.org, linux-mm@kvack.org, vdavydov.dev@gmail.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, akpm@linux-foundation.org, 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 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()? Thanks, Mark. [1] https://lkml.kernel.org/r/20190505061956.GE15755@rapoport-lnx _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel