From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id AE3356B0038 for ; Thu, 9 May 2013 17:03:18 -0400 (EDT) Date: Thu, 9 May 2013 18:03:09 -0300 From: Rafael Aquini Subject: Re: [RFC 1/2] virtio_balloon: move balloon_lock mutex to callers Message-ID: <20130509210308.GB16446@optiplex.redhat.com> References: <1368111229-29847-1-git-send-email-lcapitulino@redhat.com> <1368111229-29847-2-git-send-email-lcapitulino@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1368111229-29847-2-git-send-email-lcapitulino@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Luiz Capitulino 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 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() -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org