Re: [PATCH gnumach] smp: Create AP processor set and put all APs inside it

[Almudena Garcia]

I don't understand which is the objective of this. In an SMP system, all 
processor are equal in the scheduler. Why do you add this difference? 

El domingo 11 de febrero de 2024, Damien Zammit escribió:
> This has the effect of running with one cpu only with smp,
> but has the ability to enable APs in userspace with the right
> processor set RPCs.
> ---
>  ddb/db_print.c   |  4 +++-
>  kern/machine.c   |  7 ++++++-
>  kern/processor.c | 30 +++++++++++++++++++-----------
>  kern/processor.h |  1 +
>  4 files changed, 29 insertions(+), 13 deletions(-)
> 
> diff --git a/ddb/db_print.c b/ddb/db_print.c
> index 028cb887..b5b562fd 100644
> --- a/ddb/db_print.c
> +++ b/ddb/db_print.c
> @@ -347,8 +347,10 @@ db_show_all_runqs(
>  {
>       int i;
>  
> -     db_printf("Processor set runq:\t");
> +     db_printf("Processor set def runq:\t");
>       showrq(&default_pset.runq);
> +     db_printf("Processor set APs runq:\t");
> +     showrq(&ap_pset->runq);
>       for (i = 0; i < smp_get_numcpus(); i++) {
>           db_printf("Processor #%d runq:\t", i);
>           showrq(&cpu_to_processor(i)->runq);
> diff --git a/kern/machine.c b/kern/machine.c
> index 87fbc4d1..9fbc3871 100644
> --- a/kern/machine.c
> +++ b/kern/machine.c
> @@ -84,6 +84,7 @@ void cpu_up(int cpu)
>  
>       processor = cpu_to_processor(cpu);
>       pset_lock(&default_pset);
> +     pset_lock(ap_pset);
>       s = splsched();
>       processor_lock(processor);
>  #if  NCPUS > 1
> @@ -92,10 +93,14 @@ void cpu_up(int cpu)
>       ms = &machine_slot[cpu];
>       ms->running = TRUE;
>       machine_info.avail_cpus++;
> -     pset_add_processor(&default_pset, processor);
> +     if (cpu == 0)
> +             pset_add_processor(&default_pset, processor);
> +     else
> +             pset_add_processor(ap_pset, processor);
>       processor->state = PROCESSOR_RUNNING;
>       processor_unlock(processor);
>       splx(s);
> +     pset_unlock(ap_pset);
>       pset_unlock(&default_pset);
>  }
>  
> diff --git a/kern/processor.c b/kern/processor.c
> index 76735381..d151f497 100644
> --- a/kern/processor.c
> +++ b/kern/processor.c
> @@ -60,6 +60,7 @@ struct kmem_cache pset_cache;
>  int  master_cpu;
>  
>  struct processor_set default_pset;
> +struct processor_set *ap_pset;
>  
>  queue_head_t         all_psets;
>  int                  all_psets_count;
> @@ -67,16 +68,13 @@ def_simple_lock_data(, all_psets_lock);
>  
>  processor_t  master_processor;
>  
> -/*
> - *   Bootstrap the processor/pset system so the scheduler can run.
> - */
> -void pset_sys_bootstrap(void)
> +static void pset_sys_bootstrap_real(struct processor_set *pset, int start, 
> int count)
>  {
>       int     i;
>  
> -     pset_init(&default_pset);
> -     default_pset.empty = FALSE;
> -     for (i = 0; i < NCPUS; i++) {
> +     pset_init(pset);
> +     pset->empty = FALSE;
> +     for (i = start; i < start + count; i++) {
>               /*
>                *      Initialize processor data structures.
>                *      Note that cpu_to_processor is processor_ptr.
> @@ -86,10 +84,10 @@ void pset_sys_bootstrap(void)
>       master_processor = cpu_to_processor(master_cpu);
>       queue_init(&all_psets);
>       simple_lock_init(&all_psets_lock);
> -     queue_enter(&all_psets, &default_pset, processor_set_t, all_psets);
> -     all_psets_count = 1;
> -     default_pset.active = TRUE;
> -     default_pset.empty = FALSE;
> +     queue_enter(&all_psets, pset, processor_set_t, all_psets);
> +     all_psets_count++;
> +     pset->active = TRUE;
> +     pset->empty = FALSE;
>  
>       /*
>        *      Note: the default_pset has a max_priority of BASEPRI_USER.
> @@ -97,6 +95,14 @@ void pset_sys_bootstrap(void)
>        */
>  }
>  
> +/*
> + *   Bootstrap the processor/pset system so the scheduler can run.
> + */
> +void pset_sys_bootstrap(void)
> +{
> +     pset_sys_bootstrap_real(&default_pset, 0, NCPUS);
> +}
> +
>  #if  MACH_HOST
>  /*
>   *   Rest of pset system initializations.
> @@ -124,6 +130,8 @@ void pset_sys_init(void)
>               ipc_processor_init(processor);
>           }
>       }
> +
> +     processor_set_create(&realhost, &ap_pset, &ap_pset);
>  }
>  #endif       /* MACH_HOST */
>  
> diff --git a/kern/processor.h b/kern/processor.h
> index fc204ffa..29abc99a 100644
> --- a/kern/processor.h
> +++ b/kern/processor.h
> @@ -85,6 +85,7 @@ struct processor_set {
>       long                    sched_load;     /* load avg for scheduler */
>  };
>  extern struct processor_set  default_pset;
> +extern struct processor_set  *ap_pset;
>  
>  struct processor {
>       struct run_queue runq;          /* local runq for this processor */
> -- 
> 2.43.0
> 
> 
> 
>

-- 
Enviado desde mi dispositivo Sailfish