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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 0F3A7C38A2A for ; Thu, 7 May 2020 14:04:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B9CD82084D for ; Thu, 7 May 2020 14:04:03 +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="iELLDIcT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B9CD82084D 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 6ADA5900002; Thu, 7 May 2020 10:03:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 60FE4900011; Thu, 7 May 2020 10:03:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 46A90900002; Thu, 7 May 2020 10:03:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0079.hostedemail.com [216.40.44.79]) by kanga.kvack.org (Postfix) with ESMTP id 25527900002 for ; Thu, 7 May 2020 10:03:53 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id CDBE9824934B for ; Thu, 7 May 2020 14:03:52 +0000 (UTC) X-FDA: 76790091504.23.end15_21cee9cbce20c X-HE-Tag: end15_21cee9cbce20c X-Filterd-Recvd-Size: 6893 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Thu, 7 May 2020 14:03:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588860231; 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=tQSI93WDnJ16nEtoeWpgKm4iRZohoBJubdiofU1fO/E=; b=iELLDIcTRGoPE6e9TuTzBJ6GRrcFZQ5nxB8aZopNof2wOxHvfEAVVDt7AjwNR+MBotmJTJ ITJc58jBVsDdzHDm83dXpw3PyNC+zp373GDKdgU0/3fFaPC2VEiY17CRqWF4DOqolvlixs EZkdjLwPaJes+lb8SVny3VGCuqVOZ8U= 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-12-qfwtH60tNo6ptdwVBH69jQ-1; Thu, 07 May 2020 10:03:45 -0400 X-MC-Unique: qfwtH60tNo6ptdwVBH69jQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 81E171895950; Thu, 7 May 2020 14:03:43 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-245.ams2.redhat.com [10.36.113.245]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7EEFE60CCC; Thu, 7 May 2020 14:03:41 +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 , Pankaj Gupta Subject: [PATCH v4 15/15] virtio-mem: Try to unplug the complete online memory block first Date: Thu, 7 May 2020 16:01:39 +0200 Message-Id: <20200507140139.17083-16-david@redhat.com> In-Reply-To: <20200507140139.17083-1-david@redhat.com> References: <20200507140139.17083-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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: Right now, we always try to unplug single subblocks when processing an online memory block. Let's try to unplug the complete online memory block first, in case it is fully plugged and the unplug request is large enough. Fallback to single subblocks in case the memory block cannot get unplugged as a whole. Cc: "Michael S. Tsirkin" Cc: Pankaj Gupta Signed-off-by: David Hildenbrand --- drivers/virtio/virtio_mem.c | 88 ++++++++++++++++++++++++------------- 1 file changed, 57 insertions(+), 31 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index abd93b778a26..9e523db3bee1 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -1307,6 +1307,46 @@ static int virtio_mem_mb_unplug_any_sb_offline(str= uct virtio_mem *vm, return 0; } =20 +/* + * Unplug the given plugged subblocks of an online memory block. + * + * Will modify the state of the memory block. + */ +static int virtio_mem_mb_unplug_sb_online(struct virtio_mem *vm, + unsigned long mb_id, int sb_id, + int count) +{ + const unsigned long nr_pages =3D PFN_DOWN(vm->subblock_size) * count; + unsigned long start_pfn; + int rc; + + start_pfn =3D PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + + sb_id * vm->subblock_size); + rc =3D alloc_contig_range(start_pfn, start_pfn + nr_pages, + MIGRATE_MOVABLE, GFP_KERNEL); + if (rc =3D=3D -ENOMEM) + /* whoops, out of memory */ + return rc; + if (rc) + return -EBUSY; + + /* Mark it as fake-offline before unplugging it */ + virtio_mem_set_fake_offline(start_pfn, nr_pages, true); + adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); + + /* Try to unplug the allocated memory */ + rc =3D virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, count); + if (rc) { + /* Return the memory to the buddy. */ + virtio_mem_fake_online(start_pfn, nr_pages); + return rc; + } + + virtio_mem_mb_set_state(vm, mb_id, + VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL); + return 0; +} + /* * Unplug the desired number of plugged subblocks of an online memory bl= ock. * Will skip subblock that are busy. @@ -1321,16 +1361,21 @@ static int virtio_mem_mb_unplug_any_sb_online(str= uct virtio_mem *vm, unsigned long mb_id, uint64_t *nb_sb) { - const unsigned long nr_pages =3D PFN_DOWN(vm->subblock_size); - unsigned long start_pfn; int rc, sb_id; =20 - /* - * TODO: To increase the performance we want to try bigger, consecutive - * subblocks first before falling back to single subblocks. Also, - * we should sense via something like is_mem_section_removable() - * first if it makes sense to go ahead any try to allocate. - */ + /* If possible, try to unplug the complete block in one shot. */ + if (*nb_sb >=3D vm->nb_sb_per_mb && + virtio_mem_mb_test_sb_plugged(vm, mb_id, 0, vm->nb_sb_per_mb)) { + rc =3D virtio_mem_mb_unplug_sb_online(vm, mb_id, 0, + vm->nb_sb_per_mb); + if (!rc) { + *nb_sb -=3D vm->nb_sb_per_mb; + goto unplugged; + } else if (rc !=3D -EBUSY) + return rc; + } + + /* Fallback to single subblocks. */ for (sb_id =3D vm->nb_sb_per_mb - 1; sb_id >=3D 0 && *nb_sb; sb_id--) { /* Find the next candidate subblock */ while (sb_id >=3D 0 && @@ -1339,34 +1384,15 @@ static int virtio_mem_mb_unplug_any_sb_online(str= uct virtio_mem *vm, if (sb_id < 0) break; =20 - start_pfn =3D PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + - sb_id * vm->subblock_size); - rc =3D alloc_contig_range(start_pfn, start_pfn + nr_pages, - MIGRATE_MOVABLE, GFP_KERNEL); - if (rc =3D=3D -ENOMEM) - /* whoops, out of memory */ - return rc; - if (rc) - /* memory busy, we can't unplug this chunk */ + rc =3D virtio_mem_mb_unplug_sb_online(vm, mb_id, sb_id, 1); + if (rc =3D=3D -EBUSY) continue; - - /* Mark it as fake-offline before unplugging it */ - virtio_mem_set_fake_offline(start_pfn, nr_pages, true); - adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); - - /* Try to unplug the allocated memory */ - rc =3D virtio_mem_mb_unplug_sb(vm, mb_id, sb_id, 1); - if (rc) { - /* Return the memory to the buddy. */ - virtio_mem_fake_online(start_pfn, nr_pages); + else if (rc) return rc; - } - - virtio_mem_mb_set_state(vm, mb_id, - VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL); *nb_sb -=3D 1; } =20 +unplugged: /* * Once all subblocks of a memory block were unplugged, offline and * remove it. This will usually not fail, as no memory is in use --=20 2.25.3