Re: [PATCH v2 01/16] migration: Don't use INT64_MAX for unlimited rate

[David Edmondson <david.edmondson@oracle.com>]

Juan Quintela <quintela@redhat.com> writes:

> Define and use RATE_LIMIT_MAX instead.

Suggest "RATE_LIMIT_MAX_NONE".

>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/migration-stats.h | 6 ++++++
>  migration/migration.c       | 4 ++--
>  migration/qemu-file.c       | 6 +++++-
>  3 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/migration/migration-stats.h b/migration/migration-stats.h
> index cf8a4f0410..e782f1b0df 100644
> --- a/migration/migration-stats.h
> +++ b/migration/migration-stats.h
> @@ -15,6 +15,12 @@
>  
>  #include "qemu/stats64.h"
>  
> +/*
> + * If rate_limit_max is 0, there is special code to remove the rate
> + * limit.
> + */
> +#define RATE_LIMIT_MAX 0
> +
>  /*
>   * These are the ram migration statistic counters.  It is loosely
>   * based on MigrationStats.  We change to Stat64 any counter that
> diff --git a/migration/migration.c b/migration/migration.c
> index 039bba4804..c41c7491bb 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2304,7 +2304,7 @@ static void migration_completion(MigrationState *s)
>                   * them if migration fails or is cancelled.
>                   */
>                  s->block_inactive = !migrate_colo();
> -                qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
> +                qemu_file_set_rate_limit(s->to_dst_file, RATE_LIMIT_MAX);
>                  ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
>                                                           s->block_inactive);
>              }
> @@ -3048,7 +3048,7 @@ static void *bg_migration_thread(void *opaque)
>      rcu_register_thread();
>      object_ref(OBJECT(s));
>  
> -    qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
> +    qemu_file_set_rate_limit(s->to_dst_file, RATE_LIMIT_MAX);
>  
>      setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
>      /*
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index 597054759d..4bc875b452 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -27,6 +27,7 @@
>  #include "qemu/error-report.h"
>  #include "qemu/iov.h"
>  #include "migration.h"
> +#include "migration-stats.h"
>  #include "qemu-file.h"
>  #include "trace.h"
>  #include "options.h"
> @@ -732,7 +733,10 @@ int qemu_file_rate_limit(QEMUFile *f)

Given that qemu_file_rate_limit() is really a boolean, could it be
declared as such?

>      if (qemu_file_get_error(f)) {
>          return 1;
>      }
> -    if (f->rate_limit_max > 0 && f->rate_limit_used > f->rate_limit_max) {
> +    if (f->rate_limit_max == RATE_LIMIT_MAX) {
> +        return 0;
> +    }
> +    if (f->rate_limit_used > f->rate_limit_max) {
>          return 1;
>      }
>      return 0;
> -- 
> 2.40.1
-- 
All those lines and circles, to me, a mystery.