Linux Virtualization - Dec 2014 - [PATCH v7 36/46] vhost/net: suppress compiler warning

On Mon, Dec 01, 2014 at 01:37:40PM +0100, Cornelia Huck
wrote:
> On Sun, 30 Nov 2014 17:12:13 +0200
> "Michael S. Tsirkin" <mst at redhat.com> wrote:
> 
> > len is always initialized since function is called with size > 0.
> > 
> > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> > ---
> >  drivers/vhost/net.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> > index 984242e..54ffbb0 100644
> > --- a/drivers/vhost/net.c
> > +++ b/drivers/vhost/net.c
> > @@ -501,7 +501,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
> >  	int headcount = 0;
> >  	unsigned d;
> >  	int r, nlogs = 0;
> > -	u32 len;
> > +	u32 uninitialized_var(len);
> > 
> >  	while (datalen > 0 && headcount < quota) {
> >  		if (unlikely(seg >= UIO_MAXIOV)) {
> 
> Want to merge this with the patch introducing the variable and add a
> comment there?
Not really. Warnings in bisect are fine  I think.

-- 
MST

On Mon, 1 Dec 2014 15:48:39 +0200
"Michael S. Tsirkin" <mst at redhat.com> wrote:
> On Mon, Dec 01, 2014 at 01:37:40PM +0100, Cornelia Huck wrote:
> > On Sun, 30 Nov 2014 17:12:13 +0200
> > "Michael S. Tsirkin" <mst at redhat.com> wrote:
> > 
> > > len is always initialized since function is called with size >
0.
> > > 
> > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> > > ---
> > >  drivers/vhost/net.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> > > index 984242e..54ffbb0 100644
> > > --- a/drivers/vhost/net.c
> > > +++ b/drivers/vhost/net.c
> > > @@ -501,7 +501,7 @@ static int get_rx_bufs(struct vhost_virtqueue
*vq,
> > >  	int headcount = 0;
> > >  	unsigned d;
> > >  	int r, nlogs = 0;
> > > -	u32 len;
> > > +	u32 uninitialized_var(len);
> > > 
> > >  	while (datalen > 0 && headcount < quota) {
> > >  		if (unlikely(seg >= UIO_MAXIOV)) {
> > 
> > Want to merge this with the patch introducing the variable and add a
> > comment there?
> 
> Not really. Warnings in bisect are fine  I think.
I'm not sure what a separate patch buys us, though, as it should be
trivial to merge.

On Mon, Dec 01, 2014 at 03:21:03PM +0100, Cornelia Huck
wrote:
> On Mon, 1 Dec 2014 15:48:39 +0200
> "Michael S. Tsirkin" <mst at redhat.com> wrote:
> 
> > On Mon, Dec 01, 2014 at 01:37:40PM +0100, Cornelia Huck wrote:
> > > On Sun, 30 Nov 2014 17:12:13 +0200
> > > "Michael S. Tsirkin" <mst at redhat.com> wrote:
> > > 
> > > > len is always initialized since function is called with size
> 0.
> > > > 
> > > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> > > > ---
> > > >  drivers/vhost/net.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> > > > index 984242e..54ffbb0 100644
> > > > --- a/drivers/vhost/net.c
> > > > +++ b/drivers/vhost/net.c
> > > > @@ -501,7 +501,7 @@ static int get_rx_bufs(struct
vhost_virtqueue *vq,
> > > >  	int headcount = 0;
> > > >  	unsigned d;
> > > >  	int r, nlogs = 0;
> > > > -	u32 len;
> > > > +	u32 uninitialized_var(len);
> > > > 
> > > >  	while (datalen > 0 && headcount < quota) {
> > > >  		if (unlikely(seg >= UIO_MAXIOV)) {
> > > 
> > > Want to merge this with the patch introducing the variable and
add a
> > > comment there?
> > 
> > Not really. Warnings in bisect are fine  I think.
> 
> I'm not sure what a separate patch buys us, though, as it should be
> trivial to merge.
Easier to document the reason if it's split out.