diff options
Diffstat (limited to 'erts/doc/src/erl_nif.xml')
| -rw-r--r-- | erts/doc/src/erl_nif.xml | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 8b02b3bae1..c9b2092c17 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -442,6 +442,24 @@ ok dirty NIF has completed. </p> + <p> + It is important to classify the dirty job correct. An I/O bound + job should be classified as such and execute on a dirty I/O + scheduler, and a CPU bound job should be classified as such and + execute on a dirty CPU scheduler. If you classify CPU bound jobs + as I/O bound jobs, dirty I/O schedulers might starve ordinary + schedulers. For more information see the documentation + of the <c>erl</c> command line arguments + <seealso marker="erl#+SDcpu"><c>+SDcpu</c></seealso>, and + <seealso marker="erl#+SDio"><c>+SDio</c></seealso> as well + as <seealso marker="#enif_schedule_nif"><c>enif_schedule_nif</c></seealso>, + and <seealso marker="#ErlNifFunc"><c>ErlNifFunc</c></seealso>. + A job that alternates between I/O bound and CPU bound can + be reclassified and rescheduled using <c>enif_schedule_nif</c> + so that it exectutes on the correct type of dirty scheduler + at all times. + </p> + <p>Currently known issues that are planned to be fixed:</p> <list> <item> @@ -1702,7 +1720,7 @@ enif_map_iterator_destroy(env, &iter); be converted to an atom, <c>enif_schedule_nif</c> returns a <c>badarg</c> exception.</p> <p>The <c>flags</c> argument must be set to 0 for a regular NIF, or if the emulator was built the experimental dirty scheduler support enabled, <c>flags</c> can be set to either <c>ERL_NIF_DIRTY_JOB_CPU_BOUND</c> - if the job is expected to be primarily CPU-bound, or <c>ERL_NIF_DIRTY_JOB_IO_BOUND</c> for jobs that will + if the job is expected to be CPU-bound, or <c>ERL_NIF_DIRTY_JOB_IO_BOUND</c> for jobs that will be I/O-bound. If dirty scheduler threads are not available in the emulator, a try to schedule such a job will result in a <c>badarg</c> exception.</p> |