#8224: Excessive system time -- new IO manager problem? -------------------------------------+------------------------------------- Reporter: rrnewton | Owner: Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Runtime System | Version: 7.7 Resolution: | Keywords: IO Manager, | System Time Operating System: Linux | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #9221 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by alkar): Here is a difference between outputs for `+RTS -s` and `+RTS -N -qg -s`: https://i.imgur.com/8S5brky.png In my grep-like example, the first step is single-threaded (in the sense that I don't do any forkIO):
1. Read all lines from patterns.txt into a set.
And the pattern file can be quite large (this is why I'm doing it in a single process instead of multiprocessing), so the less penalty I get by using `-N` the better. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8224#comment:36 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler