m_linuxthr.man

unix系统下top命令的源代码

.SH "LINUX NOTES"
The Linux port was written by Richard Henderson <[e-mail]>.
The CPU% calculation was brazenly stolen from the Solaris 2
port and should be attributed to one of the many names listed
in its man page.

The order support was stolen from the SunOS 5 port by
Alexey Klimkin <[e-mail]>

Made to work under 2.4 by William LeFebvre.

This version of the Linux port includes automatic thread "eliding".
In Linux, a thread is treated as another process sharing the memory
space (as well as file table and other resources).  Thus
multiple threads appear as separate processes in most system
utilities (see
.IR clone (2)).
This version of top detects child thread processes and does not
display them separately.  Instead of displaying threads individually,
an extra column "THR" shows the number of thread processes for a
parent process.  The cpu time and percentages are added to the
parent.  This gives a display much closer to other thread-capable Unix
systems.  However, threads are still counted as separate processes in
the process summary line.
A process is considered a thread of its parent if the
following values are identical to its parent: address space size,
resident set size, code start and end program counters, and stack
start.  This heuristic can mistake a recently forked child as a thread,
until the child has either called exec or allocated space on its own.