[libvirt] [PATCHv5 06/19] util: Add monitor interface to determine path

[Wang, Huaqiang]

> -----Original Message-----
> From: John Ferlan [mailto:jferlan at redhat.com]
> Sent: Wednesday, October 10, 2018 7:16 AM
> To: Wang, Huaqiang <huaqiang.wang at intel.com>; libvir-list at redhat.com
> Cc: Feng, Shaohe <shaohe.feng at intel.com>; Niu, Bing <bing.niu at intel.com>;
> Ding, Jian-feng <jian-feng.ding at intel.com>; Zang, Rui <rui.zang at intel.com>
> Subject: Re: [libvirt] [PATCHv5 06/19] util: Add monitor interface to determine
> path
> 
> 
> 
> On 10/9/18 6:30 AM, Wang Huaqiang wrote:
> > Add interface for resctrl monitor to determine the path.
> >
> > Signed-off-by: Wang Huaqiang <huaqiang.wang at intel.com>
> > ---
> >  src/libvirt_private.syms |  1 +
> >  src/util/virresctrl.c    | 32 ++++++++++++++++++++++++++++++++
> >  src/util/virresctrl.h    |  3 +++
> >  3 files changed, 36 insertions(+)
> >
> > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index
> > 4a52a86..e175c8b 100644
> > --- a/src/libvirt_private.syms
> > +++ b/src/libvirt_private.syms
> > @@ -2681,6 +2681,7 @@ virResctrlInfoGetMonitorPrefix;
> > virResctrlInfoMonFree;  virResctrlInfoNew;  virResctrlMonitorAddPID;
> > +virResctrlMonitorDeterminePath;
> >  virResctrlMonitorNew;
> >
> >
> > diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c index
> > 03001cc..1a5578e 100644
> > --- a/src/util/virresctrl.c
> > +++ b/src/util/virresctrl.c
> > @@ -2465,3 +2465,35 @@ virResctrlMonitorAddPID(virResctrlMonitorPtr
> > monitor,  {
> >      return virResctrlAddPID(monitor->path, pid);  }
> > +
> > +int
> > +virResctrlMonitorDeterminePath(virResctrlMonitorPtr monitor,
> > +                               const char *machinename) {
> > +    char *alloc_path = NULL;
> 
> const char

OK, a pointer to const char will be better.

> 
> > +    char *parentpath = NULL;
> 
> VIR_AUTOFREE(char *) parentpath = NULL;
> 
> (thus the VIR_FREE later isn't necessary)

I haven't realized the existence of such kind of variable 'decorator'.
VIR_AUTOFREE will be used in next update.
Thanks.

> 
> > +
> > +    if (!monitor) {
> > +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> > +                       _("Invalid resctrl monitor"));
> > +        return -1;
> > +    }
> 
> Shouldn't there be a monitor->path check here like there is in
> virResctrlAllocDeterminePath?

Since virResctrlAllocDeterminePath has such kind of safety check.
Let's add the similar check here.
will be added.

> 
> > +
> > +    if (monitor->alloc)
> > +        alloc_path = monitor->alloc->path;
> > +    else
> > +        alloc_path = (char *)SYSFS_RESCTRL_PATH;
> 
> s/(char *)//

Will be removed.

> 
> > +
> > +    if (virAsprintf(&parentpath, "%s/mon_groups", alloc_path) < 0)
> > +        return -1;
> > +
> > +    monitor->path = virResctrlDeterminePath(parentpath, machinename,
> > +                                            monitor->id);
> > +
> > +    VIR_FREE(parentpath);
> 
> see above...

Line will be removed.

> 
> John

Thanks for review.
Huaqiang

> 
> > +
> > +    if (!monitor->path)
> > +        return -1;
> > +
> > +    return 0;
> > +}
> > diff --git a/src/util/virresctrl.h b/src/util/virresctrl.h index
> > cb9bfae..69b6b1d 100644
> > --- a/src/util/virresctrl.h
> > +++ b/src/util/virresctrl.h
> > @@ -196,4 +196,7 @@ virResctrlMonitorNew(void);  int
> > virResctrlMonitorAddPID(virResctrlMonitorPtr monitor,
> >                          pid_t pid);
> > +int
> > +virResctrlMonitorDeterminePath(virResctrlMonitorPtr monitor,
> > +                               const char *machinename);
> >  #endif /*  __VIR_RESCTRL_H__ */
> >