Comment 4 for bug 1394483

So, this is essentially what's suggested in the patch (with new variables to control behavior and tests to check all these):

...
+ /* New logaritmic number of pages that are estimated. We
+ first pick minimun from srv_stats_sample_pages and number of
+ pages on index. Then we pick maximum from previous number of
+ pages and log2(number of index pages) * srv_stats_sample_pages. */
   if (index->stat_index_size > 0) {
- n_sample_pages = index->stat_index_size;
+ n_sample_pages = ut_max(ut_min(srv_stats_sample_pages, index->stat_index_size),
+ log2(index->stat_index_size)*srv_stats_sample_pages);
   } else {
    n_sample_pages = 1;
...

This may surely work better than default setting or even any one picked by DBA based on some reasoning. So, I think we should consider this feature seriously (for 5.5 and for tables that do not use persistent statistics in 5.6).