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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 C1035C49EA6 for ; Thu, 24 Jun 2021 09:29:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4EC3E613F6 for ; Thu, 24 Jun 2021 09:29:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4EC3E613F6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DC9516B0036; Thu, 24 Jun 2021 05:29:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DA0376B006C; Thu, 24 Jun 2021 05:29:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C1ABC6B0071; Thu, 24 Jun 2021 05:29:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0088.hostedemail.com [216.40.44.88]) by kanga.kvack.org (Postfix) with ESMTP id 8C9EF6B0036 for ; Thu, 24 Jun 2021 05:29:41 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id A74B11F077 for ; Thu, 24 Jun 2021 09:29:41 +0000 (UTC) X-FDA: 78288094962.19.0300EE4 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf06.hostedemail.com (Postfix) with ESMTP id 45178C00CBEB for ; Thu, 24 Jun 2021 09:29:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624526980; 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=eNB6QImZTsEUvPv7cFGlcy7hZAaXO3u/PVt8yIynlso=; b=KK4u/UPheC0vmdyfDQqJXDJUrN9A5CV/uZzYbn2dikMNpW/eH1QjI7Djdp8jgAINuWttKB K/6SPRZYPZvzmiW94EGiDVQyLhRmo8X6DHXkqYY7icP9yBD2EsSW/h57pNYb5pKwHfMdIf IyLBV2owFnysA+Mi+5mxXcmCScg6giU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-90-QAp785duOPGx24QidhDU9w-1; Thu, 24 Jun 2021 05:29:36 -0400 X-MC-Unique: QAp785duOPGx24QidhDU9w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 35FFE804140; Thu, 24 Jun 2021 09:29:35 +0000 (UTC) Received: from localhost (ovpn-12-142.pek2.redhat.com [10.72.12.142]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DD8D75C1BB; Thu, 24 Jun 2021 09:29:33 +0000 (UTC) Date: Thu, 24 Jun 2021 17:29:30 +0800 From: Baoquan He To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, rientjes@google.com, rppt@linux.ibm.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, kexec@lists.infradead.org, iommu@lists.linux-foundation.org, m.szyprowski@samsung.com, robin.murphy@arm.com Subject: Re: [PATCH RFC 0/2] dma-pool: allow user to disable atomic pool Message-ID: <20210624092930.GA802261@MiWiFi-R3L-srv> References: <20210624052010.5676-1-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 45178C00CBEB X-Stat-Signature: fuif6u96r1h45g3drbz1wjm9hft6zjbx Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="KK4u/UPh"; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf06.hostedemail.com: domain of bhe@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=bhe@redhat.com X-HE-Tag: 1624526981-663511 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: On 06/24/21 at 08:40am, Christoph Hellwig wrote: > So reduce the amount allocated. But the pool is needed for proper > operation on systems with memory encryption. And please add the right > maintainer or at least mailing list for the code you're touching next > time. Oh, I thoutht it's memory issue only, should have run ./scripts/get_maintainer.pl. sorry. About reducing the amount allocated, it may not help. Because on x86_64, kdump kernel doesn't put any page of memory into buddy allocator of DMA zone. Means it will defenitely OOM for atomic_pool_dma initialization. Wondering in which case or on which device the atomic pool is needed on AMD system with mem encrytion enabled. As we can see, the OOM will happen too in kdump kernel on Intel system, even though it's not necessary. Thanks Baoquan