From patchwork Fri Dec 17 09:08:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 12683933 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 EB912C433EF for ; Fri, 17 Dec 2021 09:09:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4604B6B0075; Fri, 17 Dec 2021 04:08:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3E97D6B0078; Fri, 17 Dec 2021 04:08:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 28ACB6B007B; Fri, 17 Dec 2021 04:08:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0233.hostedemail.com [216.40.44.233]) by kanga.kvack.org (Postfix) with ESMTP id 1A7B56B0075 for ; Fri, 17 Dec 2021 04:08:56 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id C9C8B82499B9 for ; Fri, 17 Dec 2021 09:08:45 +0000 (UTC) X-FDA: 78926711010.13.9339CBD Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf10.hostedemail.com (Postfix) with ESMTP id 9F808C0014 for ; Fri, 17 Dec 2021 09:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1639732124; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DRJJuCkVZyOEZbsOujR3uAMVyJ2EnPCTOzk3f46x6zw=; b=e0c69PacukQpSlDb9PGlUbxEarx6CvNFc0WjqyqqPhNcviv4QLBog8Ytq9NTrERgsgLb/g hh36kDLob6iLTu2knNO9PtIzNgLAHaN7UFAjcqCd5VrwyRzvnCV6s0isrPX7HJcAcJhr0P gz9lEo5THbH3Yshez+AWw+7ulv1302Q= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-590-HmxlCgYLOFSU00JjNowJaA-1; Fri, 17 Dec 2021 04:08:41 -0500 X-MC-Unique: HmxlCgYLOFSU00JjNowJaA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C57EE185303D; Fri, 17 Dec 2021 09:08:39 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-164.pek2.redhat.com [10.72.12.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id D0F5D7A483; Fri, 17 Dec 2021 09:08:35 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, corbet@lwn.net, hch@lst.de, cl@linux.com, bhe@redhat.com Subject: [PATCH 2/2] dma-pool: allow user to disable atomic pool Date: Fri, 17 Dec 2021 17:08:27 +0800 Message-Id: <20211217090827.101938-3-bhe@redhat.com> In-Reply-To: <20211217090827.101938-1-bhe@redhat.com> References: <20211217090827.101938-1-bhe@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Rspamd-Queue-Id: 9F808C0014 X-Stat-Signature: bn7bcym9o8nuxbefoodcorttq4p59nxd Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=e0c69Pac; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf10.hostedemail.com: domain of bhe@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=bhe@redhat.com X-Rspamd-Server: rspam11 X-HE-Tag: 1639732120-803732 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: In the current code, three atomic memory pools are always created, atomic_pool_kernel|dma|dma32, even though 'coherent_pool=0' is specified in kernel command line. In fact, atomic pool is only necessary when CONFIG_DMA_DIRECT_REMAP=y or mem_encrypt_active=y which are needed on few ARCHes. So change code to allow user to disable atomic pool by specifying 'coherent_pool=0'. Meanwhile, update the relevant document in kernel-parameter.txt. Signed-off-by: Baoquan He Reviewed-by: Christoph Hellwig --- Documentation/admin-guide/kernel-parameters.txt | 3 ++- kernel/dma/pool.c | 7 +++++-- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index ec4d25e854a8..d7015309614b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -664,7 +664,8 @@ coherent_pool=nn[KMG] [ARM,KNL] Sets the size of memory pool for coherent, atomic dma - allocations. Otherwise the default size will be scaled + allocations. A value of 0 disables the three atomic + memory pool. Otherwise the default size will be scaled with memory capacity, while clamped between 128K and 1 << (PAGE_SHIFT + MAX_ORDER-1). diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c index 5f84e6cdb78e..5a85804b5beb 100644 --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -21,7 +21,7 @@ static struct gen_pool *atomic_pool_kernel __ro_after_init; static unsigned long pool_size_kernel; /* Size can be defined by the coherent_pool command line */ -static size_t atomic_pool_size; +static unsigned long atomic_pool_size = -1; /* Dynamic background expansion when the atomic pool is near capacity */ static struct work_struct atomic_pool_work; @@ -188,11 +188,14 @@ static int __init dma_atomic_pool_init(void) { int ret = 0; + if (!atomic_pool_size) + return 0; + /* * If coherent_pool was not used on the command line, default the pool * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER-1. */ - if (!atomic_pool_size) { + if (atomic_pool_size == -1) { unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K); pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES); atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);