From patchwork Wed Mar 11 17:14:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11432337 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 A788514B7 for ; Wed, 11 Mar 2020 17:16:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55A9E20750 for ; Wed, 11 Mar 2020 17:16:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FL32jXX4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730530AbgCKRQm (ORCPT ); Wed, 11 Mar 2020 13:16:42 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:21384 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730362AbgCKRQm (ORCPT ); Wed, 11 Mar 2020 13:16:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583947001; 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=T8uHgWgRrKhjOS0/8z1+bbTJM5VUQNPPAg1DCmOx02I=; b=FL32jXX4Augv5zDEt2Ny7FMw2F0meAKQVmM/86EqBo4z060R1Cw8rYsJAuCrNzfg4lqmBZ vI02GqiLSdI1YO6my8jytPmQYEZ/54rlIwRGN0bHFkNhytYKWIo2Ibh5q7U2eRGJ8q4Hlm fuRyqJaQoIAwY/b38Ovc0Gqpv5qyocw= 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-288-0R_hVMT8Osu2Hnt2IwParA-1; Wed, 11 Mar 2020 13:16:40 -0400 X-MC-Unique: 0R_hVMT8Osu2Hnt2IwParA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 43FB4800D5E; Wed, 11 Mar 2020 17:16:38 +0000 (UTC) Received: from t480s.redhat.com (ovpn-116-132.ams2.redhat.com [10.36.116.132]) by smtp.corp.redhat.com (Postfix) with ESMTP id C87DD60BEE; Wed, 11 Mar 2020 17:16:23 +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 , Jason Wang , Oscar Salvador , Igor Mammedov , Dave Young , Dan Williams , Pavel Tatashin , Stefan Hajnoczi , Vlastimil Babka Subject: [PATCH v2 09/10] virtio-mem: Better retry handling Date: Wed, 11 Mar 2020 18:14:21 +0100 Message-Id: <20200311171422.10484-10-david@redhat.com> In-Reply-To: <20200311171422.10484-1-david@redhat.com> References: <20200311171422.10484-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 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). 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 aa322e7732a4..48e96702d4ce 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -138,7 +138,9 @@ 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; @@ -1548,6 +1550,7 @@ 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: /* @@ -1563,8 +1566,7 @@ 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: @@ -1584,6 +1586,8 @@ 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; } @@ -1750,6 +1754,7 @@ 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);