bionic (1) threadscope.1.gz

NAME

       threadscope - a graphical thread profiler for Haskell GHC programs

SYNOPSIS

       threadscope [program.eventlog]

DESCRIPTION

       Threadscope is a graphical thread profiler for Haskell programs.

       It  parses  and  displays  the  content  of .eventlog files emitted by the GHC 6.12.1 and later runtimes,
       showing a timeline of spark creation, spark-to-thread promotions and garbage collections.

       This helps debugging the parallel performance of Haskell programs, making easier to check  that  work  is
       well  balanced across the available processors and spot performance issues relating to garbage collection
       or poor load balancing.

ARGUMENTS

       threadscope takes the name of the GHC RTS event-log file  to  process  as  its  single  argument.  If  no
       filename  is given, threadscope starts with an empty workspace, where any event-log file can be loaded by
       means of the GUI file browser facilities.

USAGE

       In order for threadscope to be useful, you have to compile your Haskell program  to  use  GHC's  threaded
       run-time  and  also  to  create runtime profile logs. This can be accomplished with the following command
       line options to ghc(1)

           $ ghc -threaded -eventlog --make Foo.hs -o foo

       Once the program is built, execute it using the multithreaded run-time, specifying  the  number  of  HECs
       (Haskell  Execution  Contexts)  to  use in the usual manner, but also requesting the creation of an event
       log. For example, to use two HECs and create an event log you would use

           $ foo +RTS -N2 -ls -RTS ...

       Once the program runs to completion, a file named foo.eventlog is produced.  You  can  start  threadscope
       from the shell prompt passing the event-log filename as the single argument, or you can start threadscope
       from the desktop menus and use its file browsing capabilities to find and open it.

SEE ALSO

       ghc(1)

AUTHOR

       threadscope was written by

           Simon Marlow <marlowsd@gmail.com>
           Donnie Jones <donnie@darthik.com>
           Satnam Singh <s.singh@ieee.org>

       This manual page was written by

           Ernesto Hernández-Novich (USB) <emhn@usb.ve>

       for the Debian project (and may be used by others).

                                                  June 28, 2010                                   THREADSCOPE(1)