lkml.org 
[lkml]   [2022]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v4 16/20] arch_topology: Drop unnecessary check for uninitialised package_id
On Tuesday 21 Jun 2022 at 20:20:30 (+0100), Sudeep Holla wrote:
> With the support of socket node parsing from the device tree and
> assigning 0 as package_id in absence of socket nodes, there is no need
> to check for invalid package_id. It is always initialised to 0 or values
> from the device tree socket nodes.
>
> Just drop that now redundant check for uninitialised package_id.
>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
> drivers/base/arch_topology.c | 11 -----------
> 1 file changed, 11 deletions(-)
>
> diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
> index 46fa1b70b02b..42448a5a9412 100644
> --- a/drivers/base/arch_topology.c
> +++ b/drivers/base/arch_topology.c
> @@ -611,7 +611,6 @@ static int __init parse_dt_topology(void)
> {
> struct device_node *cn, *map;
> int ret = 0;
> - int cpu;
>
> cn = of_find_node_by_path("/cpus");
> if (!cn) {
> @@ -633,16 +632,6 @@ static int __init parse_dt_topology(void)
>
> topology_normalize_cpu_scale();
>
> - /*
> - * Check that all cores are in the topology; the SMP code will
> - * only mark cores described in the DT as possible.
> - */
> - for_each_possible_cpu(cpu)
> - if (cpu_topology[cpu].package_id < 0) {
> - ret = -EINVAL;
> - break;
> - }
> -

Maybe it would still be good to keep this for systems with potential
errors in DT, where one forgets to add a core in cpu-map.

For example, if I modify juno.dts as follows:

--- a/arch/arm64/boot/dts/arm/juno.dts
+++ b/arch/arm64/boot/dts/arm/juno.dts
@@ -51,12 +51,9 @@ core0 {
cpu = <&A53_0>;
};
core1 {
- cpu = <&A53_1>;
- };
- core2 {
cpu = <&A53_2>;
};
- core3 {
+ core2 {
cpu = <&A53_3>;
};
};
and miss a little core in cluster1, I would end up with an incomplete
topology: core3 would have cluster_id as -1, while all other CPUs would
have a valid value; also, core3 would have package_id = -1.

Thanks,
Ionela.

> out_map:
> of_node_put(map);
> out:
> --
> 2.36.1
>

\
 
 \ /
  Last update: 2022-06-27 15:18    [W:2.018 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site