On Tue, 2019-07-23 at 16:57 +0530, Anju T Sudhakar wrote:
> Hi Qian,
>
> On 7/16/19 12:11 AM, Qian Cai wrote:
> > On Thu, 2019-07-11 at 14:53 +1000, Michael Ellerman wrote:
> > > Hi Maddy,
> > >
> > > Madhavan Srinivasan <ma...@linux.vnet.ibm.com> writes:
> > > > diff --git a/arch/powerpc/platforms/powernv/opal-imc.c
> > > > b/arch/powerpc/platforms/powernv/opal-imc.c
> > > > index 186109bdd41b..e04b20625cb9 100644
> > > > --- a/arch/powerpc/platforms/powernv/opal-imc.c
> > > > +++ b/arch/powerpc/platforms/powernv/opal-imc.c
> > > > @@ -69,20 +69,20 @@ static void export_imc_mode_and_cmd(struct
> > > > device_node
> > > > *node,
> > > > if (of_property_read_u32(node, "cb_offset", &cb_offset))
> > > > cb_offset = IMC_CNTL_BLK_OFFSET;
> > > >
> > > > - for_each_node(nid) {
> > > > - loc = (u64)(pmu_ptr->mem_info[chip].vbase) + cb_offset;
> > > > + while (ptr->vbase != NULL) {
> > >
> > > This means you'll bail out as soon as you find a node with no vbase, but
> > > it's possible we could have a CPU-less node intermingled with other
> > > nodes.
> > >
> > > So I think you want to keep the for loop, but continue if you see a NULL
> > > vbase?
> >
> > Not sure if this will also takes care of some of those messages during the
> > boot
> > on today's linux-next even without this patch.
> >
> >
> > [ 18.077780][ T1] debugfs: Directory 'imc' with parent 'powerpc'
> > already
> > present!
> >
> >
>
> This is introduced by a recent commit: c33d442328f55 (debugfs: make
> error message a bit more verbose).
>
> So basically, the debugfs imc_* file is created per node, and is created
> by the first nest unit which is
>
> being registered. For the subsequent nest units, debugfs_create_dir()
> will just return since the imc_* file already
>
> exist.
>
> The commit "c33d442328f55 (debugfs: make error message a bit more
> verbose)", prints
>
> a message if the debugfs file already exists in debugfs_create_dir().
> That is why we are encountering these
>
> messages now.
>
>
> This patch (i.e, powerpc/imc: Dont create debugfs files for cpu-less
> nodes) will address the initial issue, i.e
>
> "numa crash while reading imc_* debugfs files for cpu less nodes", and
> will not address these debugfs messages.
>
>
> But yeah this is a good catch. We can have some checks to avoid these
> debugfs messages.
Anju, do you still plan to fix those "Directory 'imc' with parent 'powerpc'
already present!" warnings as they are still there in the latest linux-next?
>
>
> Hi Michael,
>
> Do we need to have a separate patch to address these debugfs messages,
> or can we address the same
>
> in the next version of this patch itself?
>
>
> Thanks,
>
> Anju
>
>
>
>
