[GHC] #13246: hPutBuf issues unnecessary empty write syscalls for large writes

[GHC]

#13246: hPutBuf issues unnecessary empty write syscalls for large writes
-------------------------------------+-------------------------------------
        Reporter:  nh2               |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Runtime System    |              Version:  8.0.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13245            |  Differential Rev(s):  Phab:D3117
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by mpickering):

 * differential:  https://phabricator.haskell.org/D3117 => Phab:D3117


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13246#comment:5>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler