Re: [PATCH v3 06/16] arch_topology: Add support to parse and detect cache attributes

Gavin Shan
2022-06-01T03:31:21Z

Hi Sudeep,

On 5/25/22 4:14 PM, Sudeep Holla wrote:
> Currently ACPI populates just the minimum information about the last
> level cache from PPTT in order to feed the same to build sched_domains.
> Similar support for DT platforms is not present.
>
> In order to enable the same, the entire cache hierarchy information can
> be built as part of CPU topoplogy parsing both on ACPI and DT platforms.
>
> Note that this change builds the cacheinfo early even on ACPI systems, but
> the current mechanism of building llc_sibling mask remains unchanged.
>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
> drivers/base/arch_topology.c | 23 ++++++++++++++++-------
> 1 file changed, 16 insertions(+), 7 deletions(-)
>

With below nits fixed:

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
> index f73b836047cf..765723448b10 100644
> --- a/drivers/base/arch_topology.c
> +++ b/drivers/base/arch_topology.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/acpi.h>
> +#include <linux/cacheinfo.h>
> #include <linux/cpu.h>
> #include <linux/cpufreq.h>
> #include <linux/device.h>
> @@ -775,15 +776,23 @@ __weak int __init parse_acpi_topology(void)
> #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
> void __init init_cpu_topology(void)
> {
> + int ret, cpu;
> +
> reset_cpu_topology();
> + ret = parse_acpi_topology();
> + if (!ret)
> + ret = of_have_populated_dt() && parse_dt_topology();
>
> - /*
> - * Discard anything that was parsed if we hit an error so we
> - * don't use partial information.
> - */
> - if (parse_acpi_topology())
> - reset_cpu_topology();
> - else if (of_have_populated_dt() && parse_dt_topology())
> + if(ret) {
> + /*
> + * Discard anything that was parsed if we hit an error so we
> + * don't use partial information.
> + */
> reset_cpu_topology();
> + return;
> + }
> +
> + for_each_possible_cpu(cpu)
> + detect_cache_attributes(cpu);
> }
> #endif
>

# ./scripts/checkpatch.pl --codespell patch/check/0006*
ERROR: space required before the open parenthesis '('
#55: FILE: drivers/base/arch_topology.c:786:
+ if(ret) {

Thanks,
Gavin