Re: [Xen-devel] [PATCH v5 1/2] xenbus/backend: Add memory pressure handler callback

From: SeongJae Park <sj38.park@gmail.com>
To: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>, SeongJae Park <sjpark@amazon.com>,
	konrad.wilk@oracle.com, pdurrant@amazon.com,
	SeongJae Park <sjpark@amazon.de>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-block@vger.kernel.org, xen-devel@lists.xenproject.org
Subject: Re: [Xen-devel] [PATCH v5 1/2] xenbus/backend: Add memory pressure handler callback
Date: Tue, 10 Dec 2019 11:24:37 +0100	[thread overview]
Message-ID: <CAEjAshqsdjANuZDJwUnTgh3FBnhN-fp6T7-oN0hZKq8uHMDWhA@mail.gmail.com> (raw)
In-Reply-To: <20191210102023.GF980@Air-de-Roger>

On Tue, Dec 10, 2019 at 11:21 AM Roger Pau Monné <roger.pau@citrix.com> wrote:
>
> On Tue, Dec 10, 2019 at 11:16:35AM +0100, Roger Pau Monné wrote:
> > On Tue, Dec 10, 2019 at 08:06:27AM +0000, SeongJae Park wrote:
> > > diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
> > > index 869c816d5f8c..cdb075e4182f 100644
> > > --- a/include/xen/xenbus.h
> > > +++ b/include/xen/xenbus.h
> > > @@ -104,6 +104,7 @@ struct xenbus_driver {
> > >     struct device_driver driver;
> > >     int (*read_otherend_details)(struct xenbus_device *dev);
> > >     int (*is_ready)(struct xenbus_device *dev);
> > > +   unsigned (*reclaim)(struct xenbus_device *dev);
> >
> > ... hence I wonder why it's returning an unsigned when it's just
> > ignored.
> >
> > IMO it should return an int to signal errors, and the return should be
> > ignored.
>
> Meant to write 'shouldn't be ignored' sorry.

Thanks for good opinions and comments!  I will apply your comments in the next
version.

Thanks,
SeongJae Park

>
> Roger.