Re: [Qemu-devel] [PATCH v2 21/24] numa: use possible_cpus for not mapped CPUs check

[Igor Mammedov]

On Thu, 4 May 2017 14:43:12 +0200
Andrew Jones <address@hidden> wrote:

> On Wed, May 03, 2017 at 02:57:15PM +0200, Igor Mammedov wrote:
> > and remove corresponding part in numa.c that uses
> > node_cpu bitmaps.
> > 
> > Signed-off-by: Igor Mammedov <address@hidden>
> > Reviewed-by: David Gibson <address@hidden>
> > ---
> > It's one more less user of node_cpu bitmpas, following
> > commit will remove the last user along with
> > node_cpu itself.
> > ---
> >  hw/core/machine.c | 58 
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  numa.c            | 10 ----------
> >  2 files changed, 58 insertions(+), 10 deletions(-)
> > 
> > diff --git a/hw/core/machine.c b/hw/core/machine.c
> > index 217b4f4..4229054 100644
> > --- a/hw/core/machine.c
> > +++ b/hw/core/machine.c
> > @@ -19,6 +19,7 @@
> >  #include "sysemu/sysemu.h"
> >  #include "qemu/error-report.h"
> >  #include "qemu/cutils.h"
> > +#include "sysemu/numa.h"
> >  
> >  static char *machine_get_accel(Object *obj, Error **errp)
> >  {
> > @@ -648,9 +649,66 @@ bool machine_mem_merge(MachineState *machine)
> >      return machine->mem_merge;
> >  }
> >  
> > +static char *cpu_slot_to_string(const CPUArchId *cpu)
> > +{
> > +    GString *s = g_string_new(NULL);
> > +    if (cpu->props.has_socket_id) {
> > +        g_string_append_printf(s, "socket-id: %"PRId64, 
> > cpu->props.socket_id);
> > +    }
> > +    if (cpu->props.has_core_id) {
> > +        if (s->len) {
> > +            g_string_append_printf(s, ", ");
> > +        }
> > +        g_string_append_printf(s, "core-id: %"PRId64, cpu->props.core_id);
> > +    }
> > +    if (cpu->props.has_thread_id) {
> > +        if (s->len) {
> > +            g_string_append_printf(s, ", ");
> > +        }
> > +        g_string_append_printf(s, "thread-id: %"PRId64, 
> > cpu->props.thread_id);
> > +    }
> > +    return g_string_free(s, false);
> > +}
> > +
> > +static void machine_numa_validate(MachineState *machine)
> > +{
> > +    int i;
> > +    GString *s = g_string_new(NULL);
> > +    MachineClass *mc = MACHINE_GET_CLASS(machine);
> > +    const CPUArchIdList *possible_cpus = 
> > mc->possible_cpu_arch_ids(machine);
> > +
> > +    assert(nb_numa_nodes);  
> 
> Can't this be
> 
>  if (!nb_numa_nodes)
>    return;
> 
> instead? And then..
> 
> > +    for (i = 0; i < possible_cpus->len; i++) {
> > +        const CPUArchId *cpu_slot = &possible_cpus->cpus[i];
> > +
> > +        /* at this point numa mappings are initilized by CLI options
> > +         * or with default mappings so it's sufficient to list
> > +         * all not yet mapped CPUs here */
> > +        /* TODO: make it hard error in future */
> > +        if (!cpu_slot->props.has_node_id) {
> > +            char *cpu_str = cpu_slot_to_string(cpu_slot);
> > +            g_string_append_printf(s, "%sCPU %d [%s]", s->len ? ", " : "", 
> > i,
> > +                                   cpu_str);
> > +            g_free(cpu_str);
> > +        }
> > +    }
> > +    if (s->len) {
> > +        error_report("warning: CPU(s) not present in any NUMA nodes: %s",
> > +                     s->str);
> > +        error_report("warning: All CPU(s) up to maxcpus should be 
> > described "
> > +                     "in NUMA config, ability to start up with partial 
> > NUMA "
> > +                     "mappings is obsoleted and will be removed in 
> > future");
> > +    }
> > +    g_string_free(s, true);
> > +}
> > +
> >  void machine_run_board_init(MachineState *machine)
> >  {
> >      MachineClass *machine_class = MACHINE_GET_CLASS(machine);
> > +
> > +    if (nb_numa_nodes) {
> > +        machine_numa_validate(machine);
> > +    }  
> 
> ...this condition wouldn't be necessary.
I prefer to keep such conditions in the caller as during review/reading
it allows to exclude jumping into called function if condition is not
relevant for considered usecase.

> 
> >      machine_class->init(machine);
> >  }
> >  
> > diff --git a/numa.c b/numa.c
> > index f8c849d..d7aa662 100644
> > --- a/numa.c
> > +++ b/numa.c
> > @@ -293,16 +293,6 @@ static void validate_numa_cpus(void)
> >          bitmap_or(seen_cpus, seen_cpus,
> >                    numa_info[i].node_cpu, max_cpus);
> >      }
> > -
> > -    if (!bitmap_full(seen_cpus, max_cpus)) {
> > -        char *msg;
> > -        bitmap_complement(seen_cpus, seen_cpus, max_cpus);
> > -        msg = enumerate_cpus(seen_cpus, max_cpus);
> > -        error_report("warning: CPU(s) not present in any NUMA nodes: %s", 
> > msg);
> > -        error_report("warning: All CPU(s) up to maxcpus should be 
> > described "
> > -                     "in NUMA config");
> > -        g_free(msg);
> > -    }
> >      g_free(seen_cpus);
> >  }
> >  
> > -- 
> > 2.7.4
> >  
> 
> Otherwise
> Reviewed-by: Andrew Jones <address@hidden>