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| author | Christian Franke <christian.franke@t-online.de> | 2024-12-02 18:27:22 +0100 |
|---|---|---|
| committer | Corinna Vinschen <corinna@vinschen.de> | 2024-12-04 19:06:48 +0100 |
| commit | 757424f744000b0feff8693b47827d5f626434b2 (patch) | |
| tree | ac2c964bac33af6ca1c9f368646f1899b46c0b7f /winsup | |
| parent | 48b189245a135a16ea7dd16e24724820e8003221 (diff) | |
| download | newlib-757424f744000b0feff8693b47827d5f626434b2.zip newlib-757424f744000b0feff8693b47827d5f626434b2.tar.gz newlib-757424f744000b0feff8693b47827d5f626434b2.tar.bz2 | |
Cygwin: doc: document sched_setpolicy(2) and priority mapping
Document the long standing mapping from nice or sched_priority
values to Windows priority classes and the new behavior of
sched_setpolicy(8).
Signed-off-by: Christian Franke <christian.franke@t-online.de>
Diffstat (limited to 'winsup')
| -rw-r--r-- | winsup/doc/posix.xml | 34 |
1 files changed, 30 insertions, 4 deletions
diff --git a/winsup/doc/posix.xml b/winsup/doc/posix.xml index 8905691..436ab00 100644 --- a/winsup/doc/posix.xml +++ b/winsup/doc/posix.xml @@ -601,7 +601,7 @@ also IEEE Std 1003.1-2017 (POSIX.1-2017).</para> nexttowardf nexttowardl nftw - nice + nice (see <xref linkend="std-notes">chapter "Implementation Notes"</xref>) nl_langinfo nl_langinfo_l nrand48 @@ -818,8 +818,8 @@ also IEEE Std 1003.1-2017 (POSIX.1-2017).</para> sched_getparam sched_getscheduler sched_rr_get_interval - sched_setparam - sched_setscheduler + sched_setparam (see <xref linkend="std-notes">chapter "Implementation Notes"</xref>) + sched_setscheduler (see <xref linkend="std-notes">chapter "Implementation Notes"</xref>) sched_yield seed48 seekdir @@ -854,7 +854,7 @@ also IEEE Std 1003.1-2017 (POSIX.1-2017).</para> setlogmask setpgid setpgrp - setpriority + setpriority (see <xref linkend="std-notes">chapter "Implementation Notes"</xref>) setprotoent setpwent setregid @@ -1769,6 +1769,32 @@ atomic either. Over-allocation with FALLOC_FL_KEEP_SIZE is only temporary on Windows until the last handle to the file is closed. Over-allocation on sparse files is entirely ignored on Windows.</para> +<para><function>sched_setpolicy</function> only emulates API behavior +because Windows does not offer alternative scheduling policies. +If <literal>SCHED_OTHER</literal> is selected, the Windows priority is +set according to the nice value. If <literal>SCHED_FIFO</literal> +or <literal>SCHED_RR</literal> is selected, the nice value is preserved +and the Windows priority is set according to the +<literal>sched_priority</literal> value.</para> + +<para><function>nice</function>, <function>setpriority</function>, +<function>sched_setparam</function> and <function>sched_setpolicy</function> +map the nice value (<literal>SCHED_OTHER</literal>) or the +<literal>sched_priority</literal> (<literal>SCHED_FIFO</literal>, +<literal>SCHED_RR</literal>) to Windows priority classes as follows:</para> +<screen> + nice value sched_priority Windows priority class + 12...19 1....6 IDLE_PRIORITY_CLASS + 4...11 7...12 BELOW_NORMAL_PRIORITY_CLASS + -4....3 13...18 NORMAL_PRIORITY_CLASS + -12...-5 19...24 ABOVE_NORMAL_PRIORITY_CLASS + -13..-19 25...30 HIGH_PRIORITY_CLASS + -20 31...32 REALTIME_PRIORITY_CLASS +</screen> +The use of values which are mapped to the +<literal>REALTIME_PRIORITY_CLASS</literal> require administrative +privileges. + </sect1> </chapter> |