Re: [PATCH RFC 3/3] vhost, kcov: collect coverage from vhost_worker

[Andrey Konovalov]

On Thu, Oct 17, 2019 at 10:28 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu, Oct 17, 2019 at 09:00:18PM +0200, Andrey Konovalov wrote:
> > On Thu, Oct 17, 2019 at 8:18 PM Greg Kroah-Hartman
> > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > On Thu, Oct 17, 2019 at 07:44:15PM +0200, Andrey Konovalov wrote:
> > > > This patch adds kcov_remote_start/kcov_remote_stop annotations to the
> > > > vhost_worker function, which is responsible for processing vhost works.
> > > > Since vhost_worker is spawned when a vhost device instance is created,
> > > > the common kcov handle is used for kcov_remote_start/stop annotations.
> > > >
> > > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> > > > ---
> > > >  drivers/vhost/vhost.c | 15 +++++++++++++++
> > > >  drivers/vhost/vhost.h |  3 +++
> > > >  2 files changed, 18 insertions(+)
> > > >
> > > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > > > index 36ca2cf419bf..71a349f6b352 100644
> > > > --- a/drivers/vhost/vhost.c
> > > > +++ b/drivers/vhost/vhost.c
> > > > @@ -357,7 +357,13 @@ static int vhost_worker(void *data)
> > > >               llist_for_each_entry_safe(work, work_next, node, node) {
> > > >                       clear_bit(VHOST_WORK_QUEUED, &work->flags);
> > > >                       __set_current_state(TASK_RUNNING);
> > > > +#ifdef CONFIG_KCOV
> > > > +                     kcov_remote_start(dev->kcov_handle);
> > > > +#endif
> > >
> > > Shouldn't you hide these #ifdefs in a .h file?  This is not a "normal"
> > > kernel coding style at all.
> >
> > Well, if it's acceptable to add a kcov_handle field into vhost_dev
> > even when CONFIG_KCOV is not enabled, then we can get rid of those
> > #ifdefs.
>
> It should be, it's not a big deal and there's not a ton of those
> structures around that one more field is going to hurt anything...

OK, I'll do that in the next version then, thanks!