diff options
Diffstat (limited to 'erts/doc/src/erl.xml')
| -rw-r--r-- | erts/doc/src/erl.xml | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml index df80142ce1..e36d0adb0d 100644 --- a/erts/doc/src/erl.xml +++ b/erts/doc/src/erl.xml @@ -603,6 +603,24 @@ <item> <p>Force ets memory block to be moved on realloc.</p> </item> + <tag><marker id="+rg"><c><![CDATA[+rg ReaderGroupsLimit]]></c></marker></tag> + <item> + <p>Limits the amount of reader groups used by read/write locks + optimized for read operations in the Erlang runtime system. By + default the reader groups limit equals 8.</p> + <p>When the amount of schedulers is less than or equal to the reader + groups limit, each scheduler has its own reader group. When the + amount of schedulers is larger than the reader groups limit, + schedulers share reader groups. Shared reader groups degrades + read lock and read unlock performance while a large amount of + reader groups degrades write lock performance, so the limit is a + tradeoff between performance for read operations and performance + for write operations. Each reader group currently consumes 64 byte + in each read/write lock. Also note that a runtime system using + shared reader groups benefits from <seealso marker="#+sbt">binding + schedulers to logical processors</seealso>, since the reader groups + are distributed better between schedulers.</p> + </item> <tag><marker id="+S"><c><![CDATA[+S Schedulers:SchedulerOnline]]></c></marker></tag> <item> <p>Sets the amount of scheduler threads to create and scheduler @@ -667,8 +685,8 @@ <seealso marker="erlang#system_flag_scheduler_bind_type">erlang:system_flag(scheduler_bind_type, default_bind)</seealso>. </p></item> </taglist> - <p>Binding of schedulers are currently only supported on newer - Linux and Solaris systems.</p> + <p>Binding of schedulers is currently only supported on newer + Linux, Solaris, and Windows systems.</p> <p>If no CPU topology is available when the <c>+sbt</c> flag is processed and <c>BindType</c> is any other type than <c>u</c>, the runtime system will fail to start. CPU @@ -813,14 +831,28 @@ <p>For more information, see <seealso marker="erlang#system_flag_cpu_topology">erlang:system_flag(cpu_topology, CpuTopology)</seealso>.</p> </item> + <tag><marker id="+swt"><c>+swt very_low|low|medium|high|very_high</c></marker></tag> + <item> + <p>Set scheduler wakeup threshold. Default is <c>medium</c>. + The threshold determines when to wake up sleeping schedulers + when more work than can be handled by currently awake schedulers + exist. A low threshold will cause earlier wakeups, and a high + threshold will cause later wakeups. Early wakeups will + distribute work over multiple schedulers faster, but work will + more easily bounce between schedulers. + </p> + <p><em>NOTE:</em> This flag may be removed or changed at any time + without prior notice. + </p> + </item> + <tag><marker id="sched_thread_stack_size"><c><![CDATA[+sss size]]></c></marker></tag> + <item> + <p>Suggested stack size, in kilowords, for scheduler threads. + Valid range is 4-8192 kilowords. The default stack size + is OS dependent.</p> + </item> </taglist> </item> - <tag><marker id="sched_thread_stack_size"><c><![CDATA[+sss size]]></c></marker></tag> - <item> - <p>Suggested stack size, in kilowords, for scheduler threads. - Valid range is 4-8192 kilowords. The default stack size - is OS dependent.</p> - </item> <tag><marker id="+t"><c><![CDATA[+t size]]></c></marker></tag> <item> <p>Set the maximum number of atoms the VM can handle. Default is 1048576.</p> |