K 10 svn:author V 3 mav K 8 svn:date V 27 2018-08-02T21:59:46.925668Z K 7 svn:log V 677 MFV r337190: 9486 reduce memory used by device removal on fragmented pools In the most fragmented real-world cases, this reduces memory used by the mapping from ~1GB to ~50MB of RAM per 1TB of storage removed. Less fragmented cases will typically also see around 50-100MB of RAM per 1TB of storage. illumos/illumos-gate@cfd63e1b1bcf7ba4bf72f55ddbd87ce008d2986d Reviewed by: George Wilson Reviewed by: Serapheim Dimitropoulos Reviewed by: Brian Behlendorf Reviewed by: Tim Chase Approved by: Robert Mustacchi Author: Matthew Ahrens END