From patchwork Thu May 7 10:31:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11533065 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AE1E31392 for ; Thu, 7 May 2020 10:33:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 979AD21974 for ; Thu, 7 May 2020 10:33:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ew2Hx3F9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727790AbgEGKd0 (ORCPT ); Thu, 7 May 2020 06:33:26 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:42305 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727778AbgEGKdW (ORCPT ); Thu, 7 May 2020 06:33:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588847600; 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=CeHzMmu7MwOrs5WjHHH6v/xc0aAfahem/qU8YFo2Z7g=; b=Ew2Hx3F90HvZX52lrx0Ij1GB+JSPigJsI85Iv3w+s1dfG4DG6Ucbr7gtiP4mVAOIgb6MFi m9f3d1ndKqaYrOOF1akTicphWDbUa7si08AXyLJie46zPBB4wV+PYtZ++LqaEgZfnLl6aX tjVasErp0mVeXTVlJbSLxin/sWDbQCk= 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-408-9Slv2ln_MAewsJz0kKSRcw-1; Thu, 07 May 2020 06:33:17 -0400 X-MC-Unique: 9Slv2ln_MAewsJz0kKSRcw-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 59E958015D1; Thu, 7 May 2020 10:33:15 +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 193E85D9C5; Thu, 7 May 2020 10:33:03 +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 , Jason Wang , Oscar Salvador , Igor Mammedov , Dave Young , Dan Williams , Pavel Tatashin , Stefan Hajnoczi , Vlastimil Babka Subject: [PATCH v3 09/15] virtio-mem: Better retry handling Date: Thu, 7 May 2020 12:31:13 +0200 Message-Id: <20200507103119.11219-10-david@redhat.com> In-Reply-To: <20200507103119.11219-1-david@redhat.com> References: <20200507103119.11219-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Let's start with a retry interval of 5 seconds and double the time until we reach 5 minutes, in case we keep getting errors. Reset the retry interval in case we succeeded. The two main reasons for having to retry are - The hypervisor is busy and cannot process our request - We cannot reach the desired requested_size (esp., not enough memory can get unplugged because we can't allocate any subblocks). Tested-by: Pankaj Gupta Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Oscar Salvador Cc: Michal Hocko Cc: Igor Mammedov Cc: Dave Young Cc: Andrew Morton Cc: Dan Williams Cc: Pavel Tatashin Cc: Stefan Hajnoczi Cc: Vlastimil Babka Signed-off-by: David Hildenbrand --- drivers/virtio/virtio_mem.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index a2edb87e5ed8..eb4c16d634e0 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -141,7 +141,9 @@ struct virtio_mem { /* Timer for retrying to plug/unplug memory. */ struct hrtimer retry_timer; -#define VIRTIO_MEM_RETRY_TIMER_MS 30000 + unsigned int retry_timer_ms; +#define VIRTIO_MEM_RETRY_TIMER_MIN_MS 50000 +#define VIRTIO_MEM_RETRY_TIMER_MAX_MS 300000 /* Memory notifier (online/offline events). */ struct notifier_block memory_notifier; @@ -1550,6 +1552,7 @@ static void virtio_mem_run_wq(struct work_struct *work) switch (rc) { case 0: + vm->retry_timer_ms = VIRTIO_MEM_RETRY_TIMER_MIN_MS; break; case -ENOSPC: /* @@ -1565,8 +1568,7 @@ static void virtio_mem_run_wq(struct work_struct *work) */ case -ENOMEM: /* Out of memory, try again later. */ - hrtimer_start(&vm->retry_timer, - ms_to_ktime(VIRTIO_MEM_RETRY_TIMER_MS), + hrtimer_start(&vm->retry_timer, ms_to_ktime(vm->retry_timer_ms), HRTIMER_MODE_REL); break; case -EAGAIN: @@ -1586,6 +1588,8 @@ static enum hrtimer_restart virtio_mem_timer_expired(struct hrtimer *timer) retry_timer); virtio_mem_retry(vm); + vm->retry_timer_ms = min_t(unsigned int, vm->retry_timer_ms * 2, + VIRTIO_MEM_RETRY_TIMER_MAX_MS); return HRTIMER_NORESTART; } @@ -1754,6 +1758,7 @@ static int virtio_mem_probe(struct virtio_device *vdev) spin_lock_init(&vm->removal_lock); hrtimer_init(&vm->retry_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); vm->retry_timer.function = virtio_mem_timer_expired; + vm->retry_timer_ms = VIRTIO_MEM_RETRY_TIMER_MIN_MS; /* register the virtqueue */ rc = virtio_mem_init_vq(vm);