Xin LI 81f1255e58 MFV r274271:
Improve zdb -b performance:

 - Reduce gethrtime() call to 1/100th of blkptr's;
 - Skip manipulating the size-ordered tree;
 - Issue more (10, previously 3) async reads;
 - Use lighter weight testing in traverse_visitbp();

Illumos issue:
    5243 zdb -b could be much faster

MFC after:	2 weeks
2014-11-08 07:30:40 +00:00
..
2014-11-08 07:30:40 +00:00
2014-07-01 06:43:15 +00:00
2014-07-01 06:43:15 +00:00