diff options
Diffstat (limited to 'erts/doc/src/erl.xml')
| -rw-r--r-- | erts/doc/src/erl.xml | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml index 7b90a1ccca..436c2c57e1 100644 --- a/erts/doc/src/erl.xml +++ b/erts/doc/src/erl.xml @@ -915,6 +915,13 @@ number of dirty CPU schedulers online can be changed at run time via <seealso marker="erlang#system_flag_dirty_cpu_schedulers_online">erlang:system_flag(dirty_cpu_schedulers_online, DirtyCPUSchedulersOnline)</seealso>. </p> + <p> + The amount of dirty CPU schedulers is limited by the amount of + normal schedulers in order to limit the effect on processes + executing on ordinary schedulers. If the amount of dirty CPU + schedulers was allowed to be unlimited, dirty CPU bound jobs would + potentially starve normal jobs. + </p> <p>This option is ignored if the emulator doesn't have threading support enabled. Currently, <em>this option is experimental</em> and is supported only if the emulator was configured and built with support for dirty schedulers @@ -944,7 +951,7 @@ enabled (it's disabled by default). </p> </item> - <tag><marker id="+SDio"/><c><![CDATA[+SDio IOSchedulers]]></c></tag> + <tag><marker id="+SDio"/><c><![CDATA[+SDio DirtyIOSchedulers]]></c></tag> <item> <p>Sets the number of dirty I/O scheduler threads to create when threading support has been enabled. The valid range is 0-1024. By default, the number @@ -952,6 +959,16 @@ threads in the <seealso marker="#async_thread_pool_size">async thread pool </seealso>. </p> + <p> + The amount of dirty IO schedulers is not limited by the amount of + normal schedulers <seealso marker="#+SDcpu">like the amount of + dirty CPU schedulers</seealso>. This since only I/O bound work is + expected to execute on dirty I/O schedulers. I/O bound jobs are + expected to either block waiting for I/O, and/or spend a limited + amount of time moving data. However, if the user should schedule CPU + bound jobs on dirty I/O schedulers, these jobs might starve ordinary + jobs executing on ordinary schedulers. + </p> <p>This option is ignored if the emulator doesn't have threading support enabled. Currently, <em>this option is experimental</em> and is supported only if the emulator was configured and built with support for dirty schedulers |