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=-9.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 2CBEFC56201 for ; Thu, 12 Nov 2020 13:39:01 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 AE6FC22240 for ; Thu, 12 Nov 2020 13:39:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QpLxOCK4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE6FC22240 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 70071877B9; Thu, 12 Nov 2020 13:39:00 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5t0NI0wUJCHO; Thu, 12 Nov 2020 13:38:59 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id C5EDB877B4; Thu, 12 Nov 2020 13:38:59 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9FD6AC1AD8; Thu, 12 Nov 2020 13:38:59 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 0B5BFC016F for ; Thu, 12 Nov 2020 13:38:59 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 06A20870FC for ; Thu, 12 Nov 2020 13:38:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nh+AYZZrc82l for ; Thu, 12 Nov 2020 13:38:58 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by whitealder.osuosl.org (Postfix) with ESMTPS id 3DD66870E5 for ; Thu, 12 Nov 2020 13:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605188337; 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=s7b/l63zYUaR+OsccnXVvZ/uAYcvm6kvDksVTa1Mbhc=; b=QpLxOCK42KkRMngF7D57VFnVqFHpfbg7CbWaPBy4PjJ2HnjGhzlnVYMNz9ucZAie08Y1eV PUyy1J8pDgV6iP340m4CcCCn4z/ml1cLGsnk6Wt9y8u7FPcnkGHhFAUIXxpQqS/qvQVIjt X9pEN2L8ydSASkXc7u4UKqeeGaiQbJ4= 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-19-IhACjZgxNUGOglFtNSkyqg-1; Thu, 12 Nov 2020 08:38:54 -0500 X-MC-Unique: IhACjZgxNUGOglFtNSkyqg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5257018BA282; Thu, 12 Nov 2020 13:38:53 +0000 (UTC) Received: from t480s.redhat.com (ovpn-115-61.ams2.redhat.com [10.36.115.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id C589655765; Thu, 12 Nov 2020 13:38:51 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Subject: [PATCH v2 10/29] virtio-mem: retry fake-offlining via alloc_contig_range() on ZONE_MOVABLE Date: Thu, 12 Nov 2020 14:37:56 +0100 Message-Id: <20201112133815.13332-11-david@redhat.com> In-Reply-To: <20201112133815.13332-1-david@redhat.com> References: <20201112133815.13332-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Cc: Pankaj Gupta , "Michael S . Tsirkin" , virtualization@lists.linux-foundation.org, linux-mm@kvack.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" ZONE_MOVABLE is supposed to give some guarantees, yet, alloc_contig_range() isn't prepared to properly deal with some racy cases properly (e.g., temporary page pinning when exiting processed, PCP). Retry 5 times for now. There is certainly room for improvement in the future. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand --- drivers/virtio/virtio_mem.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index c24055248f9d..2f1ce4d4781b 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -784,19 +784,34 @@ static void virtio_mem_fake_online(unsigned long pfn, unsigned long nr_pages) */ static int virtio_mem_fake_offline(unsigned long pfn, unsigned long nr_pages) { - int rc; + const bool is_movable = zone_idx(page_zone(pfn_to_page(pfn))) == + ZONE_MOVABLE; + int rc, retry_count; - rc = alloc_contig_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE, - GFP_KERNEL); - if (rc == -ENOMEM) - /* whoops, out of memory */ - return rc; - if (rc) - return -EBUSY; + /* + * TODO: We want an alloc_contig_range() mode that tries to allocate + * harder (e.g., dealing with temporarily pinned pages, PCP), especially + * with ZONE_MOVABLE. So for now, retry a couple of times with + * ZONE_MOVABLE before giving up - because that zone is supposed to give + * some guarantees. + */ + for (retry_count = 0; retry_count < 5; retry_count++) { + rc = alloc_contig_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE, + GFP_KERNEL); + if (rc == -ENOMEM) + /* whoops, out of memory */ + return rc; + else if (rc && !is_movable) + break; + else if (rc) + continue; - virtio_mem_set_fake_offline(pfn, nr_pages, true); - adjust_managed_page_count(pfn_to_page(pfn), -nr_pages); - return 0; + virtio_mem_set_fake_offline(pfn, nr_pages, true); + adjust_managed_page_count(pfn_to_page(pfn), -nr_pages); + return 0; + } + + return -EBUSY; } /* -- 2.26.2 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization