Re: [Qemu-devel] [PATCH 04/31] ram: Move start time into RAMState

[Philippe Mathieu-Daudé]

On 03/16/2017 09:21 AM, Dr. David Alan Gilbert wrote:
> * Juan Quintela (address@hidden) wrote:
> > Signed-off-by: Juan Quintela <address@hidden>
>
> Reviewed-by: Dr. David Alan Gilbert <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> > ---
> >  migration/ram.c | 20 +++++++++++---------
> >  1 file changed, 11 insertions(+), 9 deletions(-)
> >
> > diff --git a/migration/ram.c b/migration/ram.c
> > index c0bee94..f6ac503 100644
> > --- a/migration/ram.c
> > +++ b/migration/ram.c
> > @@ -148,6 +148,9 @@ struct RAMState {
> >      int dirty_rate_high_cnt;
> >      /* How many times we have synchronized the bitmap */
> >      uint64_t bitmap_sync_count;
> > +    /* this variables are used for bitmap sync */
> > +    /* last time we did a full bitmap_sync */
> > +    int64_t start_time;
> >  };
> >  typedef struct RAMState RAMState;
> >
> > @@ -594,15 +597,14 @@ static void migration_bitmap_sync_range(ram_addr_t start, 
> > ram_addr_t length)
> >  }
> >
> >  /* Fix me: there are too many global variables used in migration process. */
> > -static int64_t start_time;
> >  static int64_t bytes_xfer_prev;
> >  static int64_t num_dirty_pages_period;
> >  static uint64_t xbzrle_cache_miss_prev;
> >  static uint64_t iterations_prev;
> >
> > -static void migration_bitmap_sync_init(void)
> > +static void migration_bitmap_sync_init(RAMState *rs)
> >  {
> > -    start_time = 0;
> > +    rs->start_time = 0;
> >      bytes_xfer_prev = 0;
> >      num_dirty_pages_period = 0;
> >      xbzrle_cache_miss_prev = 0;
> > @@ -640,8 +642,8 @@ static void migration_bitmap_sync(RAMState *rs)
> >          bytes_xfer_prev = ram_bytes_transferred();
> >      }
> >
> > -    if (!start_time) {
> > -        start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> > +    if (!rs->start_time) {
> > +        rs->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> >      }
> >
> >      trace_migration_bitmap_sync_start();
> > @@ -661,7 +663,7 @@ static void migration_bitmap_sync(RAMState *rs)
> >      end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> >
> >      /* more than 1 second = 1000 millisecons */
> > -    if (end_time > start_time + 1000) {
> > +    if (end_time > rs->start_time + 1000) {
> >          if (migrate_auto_converge()) {
> >              /* The following detection logic can be refined later. For now:
> >                 Check to see if the dirtied bytes is 50% more than the approx.
> > @@ -692,9 +694,9 @@ static void migration_bitmap_sync(RAMState *rs)
> >              xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
> >          }
> >          s->dirty_pages_rate = num_dirty_pages_period * 1000
> > -            / (end_time - start_time);
> > +            / (end_time - rs->start_time);
> >          s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
> > -        start_time = end_time;
> > +        rs->start_time = end_time;
> >          num_dirty_pages_period = 0;
> >      }
> >      s->dirty_sync_count = rs->bitmap_sync_count;
> > @@ -1937,7 +1939,7 @@ static int ram_save_init_globals(RAMState *rs)
> >
> >      rs->dirty_rate_high_cnt = 0;
> >      rs->bitmap_sync_count = 0;
> > -    migration_bitmap_sync_init();
> > +    migration_bitmap_sync_init(rs);
> >      qemu_mutex_init(&migration_bitmap_mutex);
> >
> >      if (migrate_use_xbzrle()) {
> > --
> > 2.9.3
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK