diff options
| -rw-r--r-- | release/doc/en_US.ISO8859-1/hardware/i386/proc-i386.sgml | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/release/doc/en_US.ISO8859-1/hardware/i386/proc-i386.sgml b/release/doc/en_US.ISO8859-1/hardware/i386/proc-i386.sgml index 2b6780b..fc48966 100644 --- a/release/doc/en_US.ISO8859-1/hardware/i386/proc-i386.sgml +++ b/release/doc/en_US.ISO8859-1/hardware/i386/proc-i386.sgml @@ -35,13 +35,19 @@ may yield some clues.</para> <para>&os; will take advantage of HyperThreading (HTT) support on - CPUs that support this feature. A kernel with the - <literal>SMP</literal> feature enabled will detect and start the + Intel CPUs that support this feature. A kernel with the + <literal>options SMP</literal> feature enabled will automatically detect the additional logical processors. The default &os; scheduler treats the logical processors the same as additional physical processors; in other words, no attempt is made to optimize scheduling decisions given the shared resources between logical - processors within the same CPU.</para> + processors within the same CPU. Because this naive scheduling can + result in suboptimal performance, the logical CPUs are halted by + default at startup. They can be enabled + with the <varname>machdep.hlt_logical_cpus</varname> sysctl + variable. It is also possible to halt any CPU in the idle + loop with the <varname>machdep.hlt_cpus</varname> sysctl + variable. The &man.smp.4; manual page has more details.</para> <para>&os; will generally run on i386-based laptops, albeit with varying levels of support for certain hardware features such as |
