MFC r272806: MFV r272802:
- Limit ARC for zdb at 256MB. zdb do not typically revisit data
in the ARC.
- Increase default max_inflight from 200 to 1000 (can be overriden
by -I) so we can queue more I/Os when doing scrubbing.
- Print status while loading meataslabs for leak detection.
Illumos issues:
5169 zdb should limit its ARC size
5170 zdb -c should create more scrub i/os by default
5171 zdb should print status while loading metaslabs for leak detection
git-svn-id: svn://svn.freebsd.org/base/stable/10@273508
ccf9f872-aa2e-dd11-9fc8-
001c23d0bc1f