From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932477AbbJVIi0 (ORCPT ); Thu, 22 Oct 2015 04:38:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34593 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756732AbbJVIiV (ORCPT ); Thu, 22 Oct 2015 04:38:21 -0400 Date: Thu, 22 Oct 2015 11:38:18 +0300 From: "Michael S. Tsirkin" To: Jason Wang Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next RFC 1/2] vhost: introduce vhost_has_work() Message-ID: <20151022113740-mutt-send-email-mst@redhat.com> References: <1445491649-62614-1-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1445491649-62614-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 22, 2015 at 01:27:28AM -0400, Jason Wang wrote: > This path introduces a helper which can give a hint for whether or not > there's a work queued in the work list. > > Signed-off-by: Jason Wang > --- > drivers/vhost/vhost.c | 6 ++++++ > drivers/vhost/vhost.h | 1 + > 2 files changed, 7 insertions(+) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index eec2f11..d42d11e 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -245,6 +245,12 @@ void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) > } > EXPORT_SYMBOL_GPL(vhost_work_queue); > > +bool vhost_has_work(struct vhost_dev *dev) > +{ > + return !list_empty(&dev->work_list); > +} > +EXPORT_SYMBOL_GPL(vhost_has_work); > + > void vhost_poll_queue(struct vhost_poll *poll) > { > vhost_work_queue(poll->dev, &poll->work); This doesn't take a lock so it's unreliable. I think it's ok in this case since it's just an optimization - but pls document this. > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 4772862..ea0327d 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -37,6 +37,7 @@ struct vhost_poll { > > void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); > void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); > +bool vhost_has_work(struct vhost_dev *dev); > > void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, > unsigned long mask, struct vhost_dev *dev); > -- > 1.8.3.1