Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752607Ab3EJMw7 (ORCPT ); Fri, 10 May 2013 08:52:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9161 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751764Ab3EJMw6 (ORCPT ); Fri, 10 May 2013 08:52:58 -0400 Date: Fri, 10 May 2013 08:52:26 -0400 From: Luiz Capitulino To: Rafael Aquini Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, riel@redhat.com, mst@redhat.com, amit.shah@redhat.com, anton@enomsg.org Subject: Re: [RFC 1/2] virtio_balloon: move balloon_lock mutex to callers Message-ID: <20130510085226.28245bcc@redhat.com> In-Reply-To: <20130509210308.GB16446@optiplex.redhat.com> References: <1368111229-29847-1-git-send-email-lcapitulino@redhat.com> <1368111229-29847-2-git-send-email-lcapitulino@redhat.com> <20130509210308.GB16446@optiplex.redhat.com> Organization: Red Hat Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3371 Lines: 84 On Thu, 9 May 2013 18:03:09 -0300 Rafael Aquini wrote: > On Thu, May 09, 2013 at 10:53:48AM -0400, Luiz Capitulino wrote: > > 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); > > I think you will need to introduce the same change as above to virtballoon_restore() Thanks Rafael, I've fixed it in my tree. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/