Re: [Qemu-devel] [PATCH 40/51] ram: Rename qemu_target_page_bits() to qemu_target_page_size()

[Peter Xu]

On Thu, Mar 23, 2017 at 09:45:33PM +0100, Juan Quintela wrote:
> It was used as a size in all cases except one.

Considering that:

- qemu_target_page_bits() is only used in migration codes, in only
  several places below

- migration codes is using TARGET_PAGE_{BITS|SIZE} a lot as well

How about we just remove this function, and directly use
TARGET_PAGE_{BITS|SIZE}?

Thanks,

> 
> Signed-off-by: Juan Quintela <address@hidden>
> ---
>  exec.c                   | 4 ++--
>  include/sysemu/sysemu.h  | 2 +-
>  migration/migration.c    | 4 ++--
>  migration/postcopy-ram.c | 8 ++++----
>  migration/savevm.c       | 8 ++++----
>  5 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index e57a8a2..9a4c385 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -3349,9 +3349,9 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong 
> addr,
>   * Allows code that needs to deal with migration bitmaps etc to still be 
> built
>   * target independent.
>   */
> -size_t qemu_target_page_bits(void)
> +size_t qemu_target_page_size(void)
>  {
> -    return TARGET_PAGE_BITS;
> +    return TARGET_PAGE_SIZE;
>  }
>  
>  #endif
> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> index 576c7ce..16175f7 100644
> --- a/include/sysemu/sysemu.h
> +++ b/include/sysemu/sysemu.h
> @@ -67,7 +67,7 @@ int qemu_reset_requested_get(void);
>  void qemu_system_killed(int signal, pid_t pid);
>  void qemu_system_reset(bool report);
>  void qemu_system_guest_panicked(GuestPanicInformation *info);
> -size_t qemu_target_page_bits(void);
> +size_t qemu_target_page_size(void);
>  
>  void qemu_add_exit_notifier(Notifier *notify);
>  void qemu_remove_exit_notifier(Notifier *notify);
> diff --git a/migration/migration.c b/migration/migration.c
> index 3f99ab3..92c3c6b 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -646,7 +646,7 @@ static void populate_ram_info(MigrationInfo *info, 
> MigrationState *s)
>      info->ram->skipped = 0;
>      info->ram->normal = norm_mig_pages_transferred();
>      info->ram->normal_bytes = norm_mig_pages_transferred() *
> -        (1ul << qemu_target_page_bits());
> +        qemu_target_page_size();
>      info->ram->mbps = s->mbps;
>      info->ram->dirty_sync_count = ram_dirty_sync_count();
>      info->ram->postcopy_requests = ram_postcopy_requests();
> @@ -2001,7 +2001,7 @@ static void *migration_thread(void *opaque)
>                 10000 is a small enough number for our purposes */
>              if (ram_dirty_pages_rate() && transferred_bytes > 10000) {
>                  s->expected_downtime = ram_dirty_pages_rate() *
> -                    (1ul << qemu_target_page_bits()) / bandwidth;
> +                    qemu_target_page_size() / bandwidth;
>              }
>  
>              qemu_file_reset_rate_limit(s->to_dst_file);
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index dc80dbb..8756364 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -123,7 +123,7 @@ bool postcopy_ram_supported_by_host(void)
>      struct uffdio_range range_struct;
>      uint64_t feature_mask;
>  
> -    if ((1ul << qemu_target_page_bits()) > pagesize) {
> +    if (qemu_target_page_size() > pagesize) {
>          error_report("Target page size bigger than host page size");
>          goto out;
>      }
> @@ -745,10 +745,10 @@ PostcopyDiscardState 
> *postcopy_discard_send_init(MigrationState *ms,
>  void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState 
> *pds,
>                                  unsigned long start, unsigned long length)
>  {
> -    size_t tp_bits = qemu_target_page_bits();
> +    size_t tp_size = qemu_target_page_size();
>      /* Convert to byte offsets within the RAM block */
> -    pds->start_list[pds->cur_entry] = (start - pds->offset) << tp_bits;
> -    pds->length_list[pds->cur_entry] = length << tp_bits;
> +    pds->start_list[pds->cur_entry] = (start - pds->offset) * tp_size;
> +    pds->length_list[pds->cur_entry] = length * tp_size;
>      trace_postcopy_discard_send_range(pds->ramblock_name, start, length);
>      pds->cur_entry++;
>      pds->nsentwords++;
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 853a81a..bbf055d 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -871,7 +871,7 @@ void qemu_savevm_send_postcopy_advise(QEMUFile *f)
>  {
>      uint64_t tmp[2];
>      tmp[0] = cpu_to_be64(ram_pagesize_summary());
> -    tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
> +    tmp[1] = cpu_to_be64(qemu_target_page_size());
>  
>      trace_qemu_savevm_send_postcopy_advise();
>      qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 16, (uint8_t *)tmp);
> @@ -1390,13 +1390,13 @@ static int 
> loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
>      }
>  
>      remote_tps = qemu_get_be64(mis->from_src_file);
> -    if (remote_tps != (1ul << qemu_target_page_bits())) {
> +    if (remote_tps != qemu_target_page_size()) {
>          /*
>           * Again, some differences could be dealt with, but for now keep it
>           * simple.
>           */
> -        error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
> -                     (int)remote_tps, 1 << qemu_target_page_bits());
> +        error_report("Postcopy needs matching target page sizes (s=%d 
> d=%zd)",
> +                     (int)remote_tps, qemu_target_page_size());
>          return -1;
>      }
>  
> -- 
> 2.9.3
> 
> 

-- peterx