Re: [RFC][PATCH v1 2/3] x86/sched: Introduce arch_rebuild_sched_domains()

Rafael J. Wysocki
2024-04-25T19:14:10Z

On Thursday, April 25, 2024 9:04:48 PM CEST Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Add arch_rebuild_sched_domains() for rebuilding scheduling domains and
> updating topology on x86 and make the ITMT code use it.
>
> First of all, this reduces code duplication somewhat and eliminates
> a need to use an extern variable, but it will also lay the ground for
> future work related to CPU capacity scaling.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This obviously is a duplicate of patch [1/3], sorry about this. My bad.

I'll send the proper patch [2/3] in a reply to this message.

> ---
> arch/x86/include/asm/topology.h | 6 ++++--
> arch/x86/kernel/itmt.c | 12 ++++--------
> arch/x86/kernel/smpboot.c | 10 +++++++++-
> 3 files changed, 17 insertions(+), 11 deletions(-)
>
> Index: linux-pm/arch/x86/include/asm/topology.h
> ===================================================================
> --- linux-pm.orig/arch/x86/include/asm/topology.h
> +++ linux-pm/arch/x86/include/asm/topology.h
> @@ -235,8 +235,6 @@ struct pci_bus;
> int x86_pci_root_bus_node(int bus);
> void x86_pci_root_bus_resources(int bus, struct list_head *resources);
>
> -extern bool x86_topology_update;
> -
> #ifdef CONFIG_SCHED_MC_PRIO
> #include <asm/percpu.h>
>
> @@ -284,9 +282,13 @@ static inline long arch_scale_freq_capac
>
> extern void arch_set_max_freq_ratio(bool turbo_disabled);
> extern void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled);
> +
> +void arch_rebuild_sched_domains(void);
> #else
> static inline void arch_set_max_freq_ratio(bool turbo_disabled) { }
> static inline void freq_invariance_set_perf_ratio(u64 ratio, bool turbo_disabled) { }
> +
> +static inline void arch_rebuild_sched_domains(void) { }
> #endif
>
> extern void arch_scale_freq_tick(void);
> Index: linux-pm/arch/x86/kernel/itmt.c
> ===================================================================
> --- linux-pm.orig/arch/x86/kernel/itmt.c
> +++ linux-pm/arch/x86/kernel/itmt.c
> @@ -54,10 +54,8 @@ static int sched_itmt_update_handler(str
> old_sysctl = sysctl_sched_itmt_enabled;
> ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
>
> - if (!ret && write && old_sysctl != sysctl_sched_itmt_enabled) {
> - x86_topology_update = true;
> - rebuild_sched_domains();
> - }
> + if (!ret && write && old_sysctl != sysctl_sched_itmt_enabled)
> + arch_rebuild_sched_domains();
>
> mutex_unlock(&itmt_update_mutex);
>
> @@ -114,8 +112,7 @@ int sched_set_itmt_support(void)
>
> sysctl_sched_itmt_enabled = 1;
>
> - x86_topology_update = true;
> - rebuild_sched_domains();
> + arch_rebuild_sched_domains();
>
> mutex_unlock(&itmt_update_mutex);
>
> @@ -150,8 +147,7 @@ void sched_clear_itmt_support(void)
> if (sysctl_sched_itmt_enabled) {
> /* disable sched_itmt if we are no longer ITMT capable */
> sysctl_sched_itmt_enabled = 0;
> - x86_topology_update = true;
> - rebuild_sched_domains();
> + arch_rebuild_sched_domains();
> }
>
> mutex_unlock(&itmt_update_mutex);
> Index: linux-pm/arch/x86/kernel/smpboot.c
> ===================================================================
> --- linux-pm.orig/arch/x86/kernel/smpboot.c
> +++ linux-pm/arch/x86/kernel/smpboot.c
> @@ -39,6 +39,7 @@
>
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>
> +#include <linux/cpuset.h>
> #include <linux/init.h>
> #include <linux/smp.h>
> #include <linux/export.h>
> @@ -125,7 +126,7 @@ static DEFINE_PER_CPU_ALIGNED(struct mwa
> int __read_mostly __max_smt_threads = 1;
>
> /* Flag to indicate if a complete sched domain rebuild is required */
> -bool x86_topology_update;
> +static bool x86_topology_update;
>
> int arch_update_cpu_topology(void)
> {
> @@ -135,6 +136,13 @@ int arch_update_cpu_topology(void)
> return retval;
> }
>
> +#ifdef CONFIG_X86_64
> +void arch_rebuild_sched_domains(void) {
> + x86_topology_update = true;
> + rebuild_sched_domains();
> +}
> +#endif
> +
> static unsigned int smpboot_warm_reset_vector_count;
>
> static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
>