Re: [PATCH v7 05/14] arm64/numa: avoid inconsistent information to be printed

Will Deacon
2016-08-30T17:51:18Z

On Sat, Aug 27, 2016 at 04:54:56PM +0800, Leizhen (ThunderTown) wrote:
>
>
> On 2016/8/26 20:47, Will Deacon wrote:
> > On Wed, Aug 24, 2016 at 03:44:44PM +0800, Zhen Lei wrote:
> >> numa_init(of_numa_init) may returned error because of numa configuration
> >> error. So "No NUMA configuration found" is inaccurate. In fact, specific
> >> configuration error information should be immediately printed by the
> >> testing branch.
> >>
> >> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> >> ---
> >> arch/arm64/mm/numa.c | 6 +++---
> >> 1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
> >> index 5bb15ea..d97c6e2 100644
> >> --- a/arch/arm64/mm/numa.c
> >> +++ b/arch/arm64/mm/numa.c
> >> @@ -335,8 +335,10 @@ static int __init numa_init(int (*init_func)(void))
> >> if (ret < 0)
> >> return ret;
> >>
> >> - if (nodes_empty(numa_nodes_parsed))
> >> + if (nodes_empty(numa_nodes_parsed)) {
> >> + pr_info("No NUMA configuration found\n");
> >> return -EINVAL;
> >
> > Hmm, but dummy_numa_init calls node_set(nid, numa_nodes_parsed) for a
> > completely artificial setup, created by adding all memblocks to node 0,
> > so this new message will be suppressed even though things really did go
> > wrong.
> It will be printed by the former: numa_init(of_numa_init)

Does that print an error for every possible failure case? What about the
acpi path?

> > In that case, don't we want to print *something* (like we do today in
> > dummy_numa_init) but maybe not "No NUMA configuration found"? What
> > exactly do you find inaccurate about the current message?
> For example:
> [ 0.000000] NUMA: No distance-matrix property in distance-map
> [ 0.000000] No NUMA configuration found
>
> So if of_numa_init or arm64_acpi_numa_init returned error, because of
> some numa configuration error had been found, it's no good to print "No
> NUMA ...".

Sure, I'm all for changing the message. I just think removing it is
probably unhelpful. Something like:

"NUMA: Failed to initialise from firmware"

might do the trick?

Will