From patchwork Thu May 9 14:53:48 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Capitulino X-Patchwork-Id: 2544321 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 1919C3FC5A for ; Thu, 9 May 2013 14:55:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755628Ab3EIOy6 (ORCPT ); Thu, 9 May 2013 10:54:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45754 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755369Ab3EIOyf (ORCPT ); Thu, 9 May 2013 10:54:35 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r49Es24X010126 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 9 May 2013 10:54:03 -0400 Received: from localhost (ovpn-113-50.phx2.redhat.com [10.3.113.50]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r49Es2fj032167; Thu, 9 May 2013 10:54:02 -0400 From: Luiz Capitulino To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, riel@redhat.com, aquini@redhat.com, mst@redhat.com, amit.shah@redhat.com, anton@enomsg.org Subject: [RFC 1/2] virtio_balloon: move balloon_lock mutex to callers Date: Thu, 9 May 2013 10:53:48 -0400 Message-Id: <1368111229-29847-2-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1368111229-29847-1-git-send-email-lcapitulino@redhat.com> References: <1368111229-29847-1-git-send-email-lcapitulino@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This commit moves the balloon_lock mutex out of the fill_balloon() and leak_balloon() functions to their callers. The reason for this change is that the next commit will introduce a shrinker callback for the balloon driver, which will also call leak_balloon() but will require different locking semantics. Signed-off-by: Luiz Capitulino --- drivers/virtio/virtio_balloon.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index bd3ae32..9d5fe2b 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -133,7 +133,6 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num) /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); - mutex_lock(&vb->balloon_lock); for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { struct page *page = balloon_page_enqueue(vb_dev_info); @@ -154,7 +153,6 @@ static void fill_balloon(struct virtio_balloon *vb, size_t num) /* Did we get any? */ if (vb->num_pfns != 0) tell_host(vb, vb->inflate_vq); - mutex_unlock(&vb->balloon_lock); } static void release_pages_by_pfn(const u32 pfns[], unsigned int num) @@ -176,7 +174,6 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num) /* We can only do one array worth at a time. */ num = min(num, ARRAY_SIZE(vb->pfns)); - mutex_lock(&vb->balloon_lock); for (vb->num_pfns = 0; vb->num_pfns < num; vb->num_pfns += VIRTIO_BALLOON_PAGES_PER_PAGE) { page = balloon_page_dequeue(vb_dev_info); @@ -192,7 +189,6 @@ static void leak_balloon(struct virtio_balloon *vb, size_t num) * is true, we *have* to do it in this order */ tell_host(vb, vb->deflate_vq); - mutex_unlock(&vb->balloon_lock); release_pages_by_pfn(vb->pfns, vb->num_pfns); } @@ -305,11 +301,13 @@ static int balloon(void *_vballoon) || freezing(current)); if (vb->need_stats_update) stats_handle_request(vb); + mutex_lock(&vb->balloon_lock); if (diff > 0) fill_balloon(vb, diff); else if (diff < 0) leak_balloon(vb, -diff); update_balloon_size(vb); + mutex_unlock(&vb->balloon_lock); } return 0; } @@ -490,9 +488,11 @@ out: static void remove_common(struct virtio_balloon *vb) { /* There might be pages left in the balloon: free them. */ + mutex_lock(&vb->balloon_lock); while (vb->num_pages) leak_balloon(vb, vb->num_pages); update_balloon_size(vb); + mutex_unlock(&vb->balloon_lock); /* Now we reset the device so we can clean up the queues. */ vb->vdev->config->reset(vb->vdev);