Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling

[OHMURA Kei]

> "We think"? I mean - yes, I think so too. But have you actually measured it?
> How much improvement are we talking here?
> Is it still faster when a bswap is involved?

Thanks for pointing out.
I will post the data for x86 later.
However, I don't have a test environment to check the impact of bswap.
Would you please measure the run time between the following section if possible?

start ->
qemu-kvm.c:

static int kvm_get_dirty_bitmap_cb(unsigned long start, unsigned long len,
                                  void *bitmap, void *opaque)
{
   /* warm up each function */
   kvm_get_dirty_pages_log_range(start, bitmap, start, len);
   kvm_get_dirty_pages_log_range_new(start, bitmap, start, len);

   /* measurement */
   int64_t t1, t2;
   t1 = cpu_get_real_ticks();
   kvm_get_dirty_pages_log_range(start, bitmap, start, len);
   t1 = cpu_get_real_ticks() - t1;
   t2 = cpu_get_real_ticks();
   kvm_get_dirty_pages_log_range_new(start, bitmap, start, len);
   t2 = cpu_get_real_ticks() - t2;

   printf("## %zd, %zd\n", t1, t2); fflush(stdout);

   return kvm_get_dirty_pages_log_range_new(start, bitmap, start, len);
}
end ->