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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 C1514C48BDF for ; Tue, 22 Jun 2021 05:49:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A71336115B for ; Tue, 22 Jun 2021 05:49:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230332AbhFVFvY (ORCPT ); Tue, 22 Jun 2021 01:51:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26862 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230204AbhFVFvX (ORCPT ); Tue, 22 Jun 2021 01:51:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624340947; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FVr7/h9402355q6HHHAllRECQ2atnyfzJmw26OaKxo0=; b=LVQOG5kyI1826A1BURXGXpqv3f9eYlNhgK/0NntQPShP02kFpIXcUVG7p21QD62YAeySvN 89syhQrq4eZzVveYQH9vliLbKwjgQSptGUkZd07vcr08o+q/rIaTKhV49iEWp3Fu1ieUIQ ckfkeTGbWHDI8cyF2hR9/c4JOYG/htY= 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-315-4zWT-7k1MwmE6BeQ6qDK5g-1; Tue, 22 Jun 2021 01:49:06 -0400 X-MC-Unique: 4zWT-7k1MwmE6BeQ6qDK5g-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 64BCC100B3B4; Tue, 22 Jun 2021 05:49:04 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-84.bne.redhat.com [10.64.54.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6CF225D9DE; Tue, 22 Jun 2021 05:48:51 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, alexander.duyck@gmail.com, david@redhat.com, mst@redhat.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, will@kernel.org, shan.gavin@gmail.com Subject: [PATCH v2 3/3] virtio_balloon: Specify page reporting order if needed Date: Tue, 22 Jun 2021 15:49:26 +0800 Message-Id: <20210622074926.333223-4-gshan@redhat.com> In-Reply-To: <20210622074926.333223-1-gshan@redhat.com> References: <20210622074926.333223-1-gshan@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The page reporting won't be triggered if the freeing page can't come up with a free area, whose size is equal or bigger than the threshold (page reporting order). The default page reporting order, equal to @pageblock_order, is too huge on some architectures to trigger page reporting. One example is ARM64 when 64KB base page size is used. PAGE_SIZE: 64KB pageblock_order: 13 (512MB) MAX_ORDER: 14 This specifies the page reporting order to 5 (2MB) for this specific case so that page reporting can be triggered. Cc: Michael S. Tsirkin Cc: David Hildenbrand Cc: virtualization@lists.linux-foundation.org Signed-off-by: Gavin Shan --- drivers/virtio/virtio_balloon.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 510e9318854d..fd419780cc23 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -993,6 +993,23 @@ static int virtballoon_probe(struct virtio_device *vdev) goto out_unregister_oom; } + /* + * The default page reporting order is @pageblock_order, which + * corresponds to 512MB in size on ARM64 when 64KB base page + * size is used. The page reporting won't be triggered if the + * freeing page can't come up with a free area like that huge. + * So we specify the page reporting order to 5, corresponding + * to 2MB. It helps to avoid THP splitting if 4KB base page + * size is used by host. + * + * Ideallh, the page reporting order is selected based on the + * host's base page size. However, it needs more work to report + * that value. The hardcoded order would be fine currently. + */ +#if defined(CONFIG_ARM64) && defined(CONFIG_ARM64_64K_PAGES) + vb->pr_dev_info.order = 5; +#endif + err = page_reporting_register(&vb->pr_dev_info); if (err) goto out_unregister_oom; -- 2.23.0