Re: [PATCH v2 3/7] scsi: libsas: optimize the debug print of the revalidate process

[Jason Yan]

On 2019/1/31 0:41, John Garry wrote:
> On 30/01/2019 08:24, Jason Yan wrote:
> > sas_rediscover() returns error code if discover failed for a expander
> > phy. And sas_ex_revalidate_domain() only returns the last phy's error
> > code. So when sas_revalidate_domain() prints the return value of the
> > discover process, we do not know if the revalidation for every phy is
> > successful or not. We just know the last bcast phy revalidation
> > succeeded or not.
> >
> > No need to return a error code for sas_ex_revalidate_domain() and
> > sas_rediscover(), and just print the debug log for each bcast phy
> > directly
> > in sas_rediscover().
>
> do we want to know about every PHY, or just the PHY where res != 0?

Here I mean every PHY that raises bcast.

> >
>
> I don't see any optimisation here. Maybe an improvement.

Thanks, I will change the wording.

> > Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
> > CC: John Garry <john.garry@xxxxxxxxxx>
> > CC: Johannes Thumshirn <jthumshirn@xxxxxxx>
> > CC: Ewan Milne <emilne@xxxxxxxxxx>
> > CC: Christoph Hellwig <hch@xxxxxx>
> > CC: Tomas Henzl <thenzl@xxxxxxxxxx>
> > CC: Dan Williams <dan.j.williams@xxxxxxxxx>
> > CC: Hannes Reinecke <hare@xxxxxxxx>
> > ---
> >  drivers/scsi/libsas/sas_discover.c |  7 +++----
> >  drivers/scsi/libsas/sas_expander.c | 11 ++++++-----
> >  include/scsi/libsas.h              |  2 +-
> >  3 files changed, 10 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/scsi/libsas/sas_discover.c
> > b/drivers/scsi/libsas/sas_discover.c
> > index 726ada9b8c79..ffc571a12916 100644
> > --- a/drivers/scsi/libsas/sas_discover.c
> > +++ b/drivers/scsi/libsas/sas_discover.c
> > @@ -500,7 +500,6 @@ static void sas_discover_domain(struct work_struct
> > *work)
> >
> >  static void sas_revalidate_domain(struct work_struct *work)
> >  {
> > -    int res = 0;
> >      struct sas_discovery_event *ev = to_sas_discovery_event(work);
> >      struct asd_sas_port *port = ev->port;
> >      struct sas_ha_struct *ha = port->ha;
> > @@ -521,10 +520,10 @@ static void sas_revalidate_domain(struct
> > work_struct *work)
> >
> >      if (ddev && (ddev->dev_type == SAS_FANOUT_EXPANDER_DEVICE ||
> >               ddev->dev_type == SAS_EDGE_EXPANDER_DEVICE))
> > -        res = sas_ex_revalidate_domain(ddev);
> > +        sas_ex_revalidate_domain(ddev);
> >
> > -    pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
> > -         port->id, task_pid_nr(current), res);
> > +    pr_debug("done REVALIDATING DOMAIN on port %d, pid:%d\n",
> > +         port->id, task_pid_nr(current));
> >   out:
> >      mutex_unlock(&ha->disco_mutex);
> >
> > diff --git a/drivers/scsi/libsas/sas_expander.c
> > b/drivers/scsi/libsas/sas_expander.c
> > index 7b0e6dcef6e6..5cd720f93f96 100644
> > --- a/drivers/scsi/libsas/sas_expander.c
> > +++ b/drivers/scsi/libsas/sas_expander.c
> > @@ -2062,7 +2062,7 @@ static int sas_rediscover_dev(struct
> > domain_device *dev, int phy_id, bool last)
> >   * first phy,for other phys in this port, we add it to the port to
> >   * forming the wide-port.
> >   */
> > -static int sas_rediscover(struct domain_device *dev, const int phy_id)
> > +static void sas_rediscover(struct domain_device *dev, const int phy_id)
> >  {
> >      struct expander_device *ex = &dev->ex_dev;
> >      struct ex_phy *changed_phy = &ex->ex_phy[phy_id];
> > @@ -2090,7 +2090,9 @@ static int sas_rediscover(struct domain_device
> > *dev, const int phy_id)
> >          res = sas_rediscover_dev(dev, phy_id, last);
> >      } else
> >          res = sas_discover_new(dev, phy_id);
> > -    return res;
> > +
> > +    pr_debug("ex %016llx phy%d discover returned 0x%x\n",
>
> Hmmm.. this is not just discover, but also rediscover

Yes, will fix.

> > +         SAS_ADDR(dev->sas_addr), phy_id, res);
> >  }
> >
> >  /**
> > @@ -2102,7 +2104,7 @@ static int sas_rediscover(struct domain_device
> > *dev, const int phy_id)
> >   * Discover process only interrogates devices in order to discover the
> >   * domain.
> >   */
> > -int sas_ex_revalidate_domain(struct domain_device *port_dev)
> > +void sas_ex_revalidate_domain(struct domain_device *port_dev)
> >  {
> >      int res;
> >      struct domain_device *dev = NULL;
> > @@ -2117,11 +2119,10 @@ int sas_ex_revalidate_domain(struct
> > domain_device *port_dev)
> >              res = sas_find_bcast_phy(dev, &phy_id, i, true);
>
> this was missed

Yes, the return value of sas_find_bcast_phy() is actually unused, and
inside the function debug info has been printed. So we can directly
make it a void function.

> >              if (phy_id == -1)
> >                  break;
> > -            res = sas_rediscover(dev, phy_id);
> > +            sas_rediscover(dev, phy_id);
> >              i = phy_id + 1;
> >          } while (i < ex->num_phys);
> >      }
> > -    return res;
> >  }
> >
> >  void sas_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
> > diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
> > index 420156cea3ee..e557bcb0c266 100644
> > --- a/include/scsi/libsas.h
> > +++ b/include/scsi/libsas.h
> > @@ -692,7 +692,7 @@ int  sas_discover_root_expander(struct
> > domain_device *);
> >
> >  void sas_init_ex_attr(void);
> >
> > -int  sas_ex_revalidate_domain(struct domain_device *);
> > +void sas_ex_revalidate_domain(struct domain_device *);
> >
> >  void sas_unregister_domain_devices(struct asd_sas_port *port, int gone);
> >  void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *);
>
>
>
> .