f348575edc
Prior to this patch, top was able to handle any hotplugged
cpus *added* to the system in two distinct ways.
1) Newly added cpus would be detected by sysinfo_refresh
calling the library's cpuinfo function, which occurs
at most every 5 minutes.
2) The user could force a refresh using either the
<Enter> or <Space> keys.
Unfortunately, the *loss* of a cpu would produce an early
exit due to a /proc/stat read failure. Such a failure
can be produced in the following way:
sudo echo 0 > /sys/devices/system/cpu/cpu??/online
This commit allows top to tolerate the loss of cpus.
It also provides for more efficient CPU_t management,
especially for massively parallel cpu environments.
Note: Changes to the cpu compliment can produce a single
cycle distortion of cpu percentages. Such distortion is
most visible when each cpu is being displayed. It can
be eliminated with a forced refresh via <Enter>/<Space>.
COMPATIBILITY
This code is intended for use with Linux 2.2.xx, 2.4.xx,
2.6.xx, and hopefully all future kernels. You should be
running a system with libc 6, but libc 5 might work too.
INSTALLATION
make
make install
Only the second ("make install") is needed if you just
want to build and install procps-ng in the normal way.
If you wish to test before installing, use the scripts
named t, v, and p to ensure that the correct libproc
(the new one) is used during your testing.
You may set SKIP to avoid building or installing things.
For example:
make SKIP='/bin/kill /usr/share/man/man1/kill.1' install
Use SHARED=0 to build procps-ng without shared libraries.
This may be useful for installing in your home directory.
make SHARED=0 DESTDIR=$HOME install
Suppose you wanted to install stuff in strange places.
You might do something like this:
make usr/bin=/tmp/Q/i/ DESTDIR=/tmp/Q install="install -D" ldconfig=echo install
If cross-compiling, you might need to set lib64 to
either "lib" or "lib64". You might need to set m64 to
-m64, -m32, or nothing at all. Some examples:
make lib64=lib m64=-m32 # for a bi-arch gcc
make lib64=lib64 CC=x86_64-gcc
make lib64=lib CC=alpha-gcc
PACKAGING
If you are a downstream maintainer (packager) for a Linux distribution,
please avoid causing troubles. This section applies to you.
Send patches in regularly. Many patches made by vendors have been buggy,
some quite severely so. Sending in a patch will at least get it reviewed,
if not included. There is a procps-ng test suite that must be passed.
Forward all bug reports. If your bug database is public and busy enough
to bother with, please make this known. Follow Debian's lead in making
the bug database easy to comment on via email w/o need for an account.
Do not change the user interface. Many of the programs are intended to be
compatible with Solaris, FreeBSD, AIX, IRIX, Tru64, and the UNIX standard.
Your nice new command options WILL BE BROKEN as needed to ensure that
procps-ng remains compatible with the rest of the world. Sysadmins hate to
deal with incompatible behavior. If you need a new option, ask for it.
For normal packages, ensure that you do not add debugging flags
to the CFLAGS variable. If debugging flags are present, the Makefile
will avoid adding several optimizations that would interfere with gdb.
There should be no need to modify the Makefile. You can set variables
on the "make" command line or use "make -e" to pass variables from
the environment.
BUG REPORTS
Email to procps@freelists.org.