Re: [PATCH 1/7] migration: Drop dead code of ram_debug_dump_bitmap()

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Peter Xu (peterx@redhat.com) wrote:
> I planned to add "#ifdef DEBUG_POSTCOPY" around the function too because
> otherwise it'll be compiled into qemu binary even if it'll never be used.  Then
> I found that maybe it's easier to just drop it for good..
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>

Yeh, it was useful debugging the bitmap in the early days.


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Dave
> ---
>  migration/ram.c | 39 ---------------------------------------
>  migration/ram.h |  2 --
>  2 files changed, 41 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 863035d235..756ac800a7 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2413,40 +2413,6 @@ static void ram_state_reset(RAMState *rs)
>  
>  #define MAX_WAIT 50 /* ms, half buffered_file limit */
>  
> -/*
> - * 'expected' is the value you expect the bitmap mostly to be full
> - * of; it won't bother printing lines that are all this value.
> - * If 'todump' is null the migration bitmap is dumped.
> - */
> -void ram_debug_dump_bitmap(unsigned long *todump, bool expected,
> -                           unsigned long pages)
> -{
> -    int64_t cur;
> -    int64_t linelen = 128;
> -    char linebuf[129];
> -
> -    for (cur = 0; cur < pages; cur += linelen) {
> -        int64_t curb;
> -        bool found = false;
> -        /*
> -         * Last line; catch the case where the line length
> -         * is longer than remaining ram
> -         */
> -        if (cur + linelen > pages) {
> -            linelen = pages - cur;
> -        }
> -        for (curb = 0; curb < linelen; curb++) {
> -            bool thisbit = test_bit(cur + curb, todump);
> -            linebuf[curb] = thisbit ? '1' : '.';
> -            found = found || (thisbit != expected);
> -        }
> -        if (found) {
> -            linebuf[curb] = '\0';
> -            fprintf(stderr,  "0x%08" PRIx64 " : %s\n", cur, linebuf);
> -        }
> -    }
> -}
> -
>  /* **** functions for postcopy ***** */
>  
>  void ram_postcopy_migrated_memory_release(MigrationState *ms)
> @@ -2674,11 +2640,6 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
>          if (ret) {
>              return ret;
>          }
> -
> -#ifdef DEBUG_POSTCOPY
> -        ram_debug_dump_bitmap(block->bmap, true,
> -                              block->used_length >> TARGET_PAGE_BITS);
> -#endif
>      }
>      trace_ram_postcopy_send_discard_bitmap();
>  
> diff --git a/migration/ram.h b/migration/ram.h
> index c515396a9a..f543e25765 100644
> --- a/migration/ram.h
> +++ b/migration/ram.h
> @@ -55,8 +55,6 @@ void mig_throttle_counter_reset(void);
>  uint64_t ram_pagesize_summary(void);
>  int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
>  void acct_update_position(QEMUFile *f, size_t size, bool zero);
> -void ram_debug_dump_bitmap(unsigned long *todump, bool expected,
> -                           unsigned long pages);
>  void ram_postcopy_migrated_memory_release(MigrationState *ms);
>  /* For outgoing discard bitmap */
>  int ram_postcopy_send_discard_bitmap(MigrationState *ms);
> -- 
> 2.32.0
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK