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

On 2016/8/31 1:51, Will Deacon wrote:

On Sat, Aug 27, 2016 at 04:54:56PM +0800, Leizhen (ThunderTown) wrote:

quoted

On 2016/8/26 20:47, Will Deacon wrote:

quoted

On Wed, Aug 24, 2016 at 03:44:44PM +0800, Zhen Lei wrote:

quoted

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 <redacted>
---
 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?

I think acpi path should print error by itself. The reason maybe:
1. In numa_init and its sub function, all error paths printed error immediately, except arm64_acpi_numa_init.
2. Suppose numa_init returns error, we do not print the returned error code, so the user don't known what problem cause acpi numa failed.

quoted

quoted

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"

I think adding this into arm64_acpi_numa_init will be better, maybe we should print 'ret' further:

int __init arm64_acpi_numa_init(void)
{
	int ret;

	ret = acpi_numa_init();
	if (ret) {
+		pr_info("Failed to initialise from firmware\n");
		return ret;
	}

might do the trick?

Will

.

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html