| Message ID | 1460457796-1779-2-git-send-email-wei.liu2@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 12 Apr 2016, Wei Liu wrote: > In commit ac0487e1 ("xenfb.c: avoid expensive loops when prod <= > out_cons"), ">=" was used. In fact, a full ring is a legit state. > Correct the test to use ">". > > Reported-by: "Hao, Xudong" <xudong.hao@intel.com> > Signed-off-by: Wei Liu <wei.liu2@citrix.com> > Tested-by: "Hao, Xudong" <xudong.hao@intel.com> > Acked-by: Anthony Perard <anthony.perard@citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> I'll add it to my queue > Cc: Stefano Stabellini <sstabellini@kernel.org> > Cc: Anthony Perard <anthony.perard@citrix.com> > > Backport candidate to our own tree. > --- > hw/display/xenfb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c > index 40b096a..9866dfd 100644 > --- a/hw/display/xenfb.c > +++ b/hw/display/xenfb.c > @@ -775,7 +775,7 @@ static void xenfb_handle_events(struct XenFB *xenfb) > > prod = page->out_prod; > out_cons = page->out_cons; > - if (prod - out_cons >= XENFB_OUT_RING_LEN) { > + if (prod - out_cons > XENFB_OUT_RING_LEN) { > return; > } > xen_rmb(); /* ensure we see ring contents up to prod */ > -- > 2.1.4 >
On Tue, Apr 12, 2016 at 10:12:28AM -0700, Stefano Stabellini wrote: > On Tue, 12 Apr 2016, Wei Liu wrote: > > In commit ac0487e1 ("xenfb.c: avoid expensive loops when prod <= > > out_cons"), ">=" was used. In fact, a full ring is a legit state. > > Correct the test to use ">". > > > > Reported-by: "Hao, Xudong" <xudong.hao@intel.com> > > Signed-off-by: Wei Liu <wei.liu2@citrix.com> > > Tested-by: "Hao, Xudong" <xudong.hao@intel.com> > > Acked-by: Anthony Perard <anthony.perard@citrix.com> > > Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > I'll add it to my queue > > > > Cc: Stefano Stabellini <sstabellini@kernel.org> > > Cc: Anthony Perard <anthony.perard@citrix.com> > > > > Backport candidate to our own tree. Patch backported to qemu-xen.git:master.
On Fri, Apr 22, 2016 at 12:16:09PM +0100, Anthony PERARD wrote: > On Tue, Apr 12, 2016 at 10:12:28AM -0700, Stefano Stabellini wrote: > > On Tue, 12 Apr 2016, Wei Liu wrote: > > > In commit ac0487e1 ("xenfb.c: avoid expensive loops when prod <= > > > out_cons"), ">=" was used. In fact, a full ring is a legit state. > > > Correct the test to use ">". > > > > > > Reported-by: "Hao, Xudong" <xudong.hao@intel.com> > > > Signed-off-by: Wei Liu <wei.liu2@citrix.com> > > > Tested-by: "Hao, Xudong" <xudong.hao@intel.com> > > > Acked-by: Anthony Perard <anthony.perard@citrix.com> > > > > Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > > > I'll add it to my queue > > > > > > > Cc: Stefano Stabellini <sstabellini@kernel.org> > > > Cc: Anthony Perard <anthony.perard@citrix.com> > > > > > > Backport candidate to our own tree. > > Patch backported to qemu-xen.git:master. > I think you mean staging. :-) Wei. > -- > Anthony PERARD
diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c index 40b096a..9866dfd 100644 --- a/hw/display/xenfb.c +++ b/hw/display/xenfb.c @@ -775,7 +775,7 @@ static void xenfb_handle_events(struct XenFB *xenfb) prod = page->out_prod; out_cons = page->out_cons; - if (prod - out_cons >= XENFB_OUT_RING_LEN) { + if (prod - out_cons > XENFB_OUT_RING_LEN) { return; } xen_rmb(); /* ensure we see ring contents up to prod */
In commit ac0487e1 ("xenfb.c: avoid expensive loops when prod <= out_cons"), ">=" was used. In fact, a full ring is a legit state. Correct the test to use ">". Reported-by: "Hao, Xudong" <xudong.hao@intel.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Tested-by: "Hao, Xudong" <xudong.hao@intel.com> Acked-by: Anthony Perard <anthony.perard@citrix.com> --- Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Anthony Perard <anthony.perard@citrix.com> Backport candidate to our own tree. --- hw/display/xenfb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)