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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 65A7DC2D0CA for ; Thu, 12 Dec 2019 17:13:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2D440205C9 for ; Thu, 12 Dec 2019 17:13:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YTAZqjSC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D440205C9 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 D2BB68E000F; Thu, 12 Dec 2019 12:13:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CDC178E0001; Thu, 12 Dec 2019 12:13:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7D728E000F; Thu, 12 Dec 2019 12:13:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0206.hostedemail.com [216.40.44.206]) by kanga.kvack.org (Postfix) with ESMTP id A15CD8E0001 for ; Thu, 12 Dec 2019 12:13:36 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 46DE52497 for ; Thu, 12 Dec 2019 17:13:36 +0000 (UTC) X-FDA: 76257136032.25.skate05_76b87c96f5b4c X-HE-Tag: skate05_76b87c96f5b4c X-Filterd-Recvd-Size: 6064 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Thu, 12 Dec 2019 17:13:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576170815; 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=w/9RPsLV3hmHV/aDZLnceRyys47s4obu7zT1ywSY+3U=; b=YTAZqjSCLBiEE8kML0HOJn5E9JOKVc33ekj4DXHQypAKD/iRzyytggRDD8Q9P340+IZhbb 1cO/fkgBUnhgu1N4vj3T3VILZS86pNh/NSvgpU7yYOCWhbEA+bBpOzsbD8rJfuiDphBQsg R17b1xCkZDcGayWbhRQedmmm+AuUXXk= 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-230-ugnwkmHgMqya7HmLmDbz_g-1; Thu, 12 Dec 2019 12:13:31 -0500 X-MC-Unique: ugnwkmHgMqya7HmLmDbz_g-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 546F1800053; Thu, 12 Dec 2019 17:13:29 +0000 (UTC) Received: from t480s.redhat.com (ovpn-117-65.ams2.redhat.com [10.36.117.65]) by smtp.corp.redhat.com (Postfix) with ESMTP id C082A5C1C3; Thu, 12 Dec 2019 17:13:25 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, Michal Hocko , Andrew Morton , "Michael S . Tsirkin" , David Hildenbrand , Alexander Viro , Jason Wang , Oscar Salvador , Igor Mammedov , Dave Young , Dan Williams , Pavel Tatashin , Stefan Hajnoczi , Vlastimil Babka , linux-fsdevel@vger.kernel.org Subject: [PATCH RFC v4 13/13] virtio-mem: Drop slab objects when unplug continues to fail Date: Thu, 12 Dec 2019 18:11:37 +0100 Message-Id: <20191212171137.13872-14-david@redhat.com> In-Reply-To: <20191212171137.13872-1-david@redhat.com> References: <20191212171137.13872-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Content-Transfer-Encoding: quoted-printable 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: Start dropping slab objects after 30 minutes and repeat every 30 minutes in case we can't unplug more memory using alloc_contig_range(). Log messages and make it configurable. Enable dropping slab objects as default (especially, reclaimable slab objects that are not movable). In the future, we might want to implement+use drop_slab_range(), which will also come in handy for other users (e.g., offlining, gigantic huge pages). Cc: Alexander Viro Cc: Andrew Morton Cc: Michal Hocko Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Oscar Salvador Cc: Igor Mammedov Cc: Dave Young Cc: Dan Williams Cc: Pavel Tatashin Cc: Stefan Hajnoczi Cc: Vlastimil Babka Cc: linux-fsdevel@vger.kernel.org Signed-off-by: David Hildenbrand --- drivers/virtio/virtio_mem.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 3a57434f92ed..8f25f7453a08 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -25,6 +25,11 @@ static bool unplug_online =3D true; module_param(unplug_online, bool, 0644); MODULE_PARM_DESC(unplug_online, "Try to unplug online memory"); =20 +static bool drop_slab_objects =3D true; +module_param(drop_slab_objects, bool, 0644); +MODULE_PARM_DESC(drop_slab_objects, + "Drop slab objects when unplug continues to fail"); + enum virtio_mem_mb_state { /* Unplugged, not added to Linux. Can be reused later. */ VIRTIO_MEM_MB_STATE_UNUSED =3D 0, @@ -1384,6 +1389,7 @@ static int virtio_mem_mb_unplug_any_sb_online(struc= t virtio_mem *vm, static int virtio_mem_unplug_request(struct virtio_mem *vm, uint64_t dif= f) { uint64_t nb_sb =3D diff / vm->subblock_size; + bool retried =3D false; unsigned long mb_id; int rc; =20 @@ -1421,6 +1427,7 @@ static int virtio_mem_unplug_request(struct virtio_= mem *vm, uint64_t diff) return 0; } =20 +retry_locked: /* Try to unplug subblocks of partially plugged online blocks. */ virtio_mem_for_each_mb_state(vm, mb_id, VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL) { @@ -1445,6 +1452,29 @@ static int virtio_mem_unplug_request(struct virtio= _mem *vm, uint64_t diff) } =20 mutex_unlock(&vm->hotplug_mutex); + + /* + * If we can't unplug the requested amount of memory for a long time, + * start freeing up memory in caches. This might harm performance, + * is configurable, and we log a message. Retry imemdiately a second + * time - then wait another VIRTIO_MEM_RETRY_TIMER_MAX_MS. + */ + if (nb_sb && !retried && drop_slab_objects && + vm->retry_timer_ms =3D=3D VIRTIO_MEM_RETRY_TIMER_MAX_MS) { + if (vm->nid =3D=3D NUMA_NO_NODE) { + dev_info(&vm->vdev->dev, "dropping all slab objects\n"); + drop_slab(); + } else { + dev_info(&vm->vdev->dev, + "dropping all slab objects on node=3D%d\n", + vm->nid); + drop_slab_node(vm->nid); + } + retried =3D true; + mutex_lock(&vm->hotplug_mutex); + goto retry_locked; + } + return nb_sb ? -EBUSY : 0; out_unlock: mutex_unlock(&vm->hotplug_mutex); --=20 2.23.0