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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 20:34:44 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 20:34:44 +0000
commite3be059d4da38aa36f1aee1d56f8ceb943d92f1c (patch)
tree26edef31e4e503dd1c92a112de174f366dd61802 /doc/FAQ
parentInitial commit. (diff)
downloadprocps-e3be059d4da38aa36f1aee1d56f8ceb943d92f1c.tar.xz
procps-e3be059d4da38aa36f1aee1d56f8ceb943d92f1c.zip
Adding upstream version 2:4.0.4.upstream/2%4.0.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+Why does "ps -aux" complain about a bogus '-'?
+
+ According to the POSIX and UNIX standards, the above command asks to
+ display all processes with a TTY (generally the commands users are
+ running) plus all processes owned by a user named "x". If that user
+ doesn't exist, then ps will assume you really meant "ps aux". The
+ warning is given to gently break you of a habit that will cause you
+ trouble if a user named "x" were created.
+
+Why don't I see SMP (per-CPU) stats in top?
+
+ You didn't enable it. Press '?' for built-in help or read the man
+ page. Per-CPU stats are disabled by default because they take up too
+ much space. Some Linux systems have hundreds of CPUs.
+
+Why do long usernames get printed as numbers?
+
+ The UNIX and POSIX standards require that user names and group names
+ be printed as decimal integers when there is not enough room in the
+ column. Truncating the names, besides being a violation of the
+ standard, would lead to confusion between names like MichelleRichards
+ and MichelleRichardson. The UNIX and POSIX way to change column
+ width is to rename the column:
+
+ ps -o pid,user=CumbersomeUserNames -o comm
+
+ The easy way is to directly specify the desired width:
+
+ ps -o pid,user:19,comm
+
+Why is %CPU underreported for multi-threaded (Java, etc.) apps?
+
+ You need to upgrade to the 2.6.10 kernel at least. Older kernels do
+ not provide a reasonable way to get this information.
+
+Why do ps and top show threads individually?
+
+ The 2.4.xx kernel does not provide proper support for grouping
+ threads by process. Hacks exist to group them anyway, but such hacks
+ will falsely group similar tasks and will fail to group tasks due to
+ race conditions. The hacks are also slow. As none of this is
+ acceptable in a critical system tool, task grouping is not currently
+ available for the 2.4.xx kernel. The 2.6.xx kernel allows for proper
+ thread grouping and reporting. To take advantage of this, your
+ programs must use a threading library that features the CLONE_THREAD
+ flag. The NPTL pthreads provided by recent glibc releases use
+ CLONE_THREAD.
+
+What systems are supported?
+
+ Linux 2.4.xx 2.6.xx and 3.xx are commonly tested and expected to work
+ well. SMP is well supported. Multi-node cluster views require a
+ multi-node /proc filesystem; without that you will see a single-node
+ view.
+
+Where to I send bug reports?
+
+ You may use the Debian bug tracking system or send your report to
+ procps@freelists.org (no subscription required) instead.
+
+Why are there so many procps projects?
+
+ The original maintainer seems to have had little time for procps.
+ Whatever his reasons, the project didn't get maintained. Starting in
+ 1997, Albert Cahalan wrote a new ps program for the package. For the
+ next few years, Albert quietly helped the Debian package maintainer
+ fix bugs. In 2001, Rik van Riel decided to do something about what
+ appeared to be the lack of a maintainer. He picked up the buggy old
+ code in Red Hat's CVS and started adding patches. Meanwhile, other
+ people have patched procps in a great many ways.
+
+ In 2002, Albert moved procps to http://procps.sourceforge.net. This
+ was done to ensure that years of testing and bug fixes would not be
+ lost. The major version number was changed to 3, partly to avoid
+ confusing users and partly because the top program had been redone.
+
+ After development essentially stopped on sourceforge.net, in 2011 the
+ project found a new home at http://gitorious.org/procps. This
+ represents the Debian, Fedora and openSUSE fork of procps. To avoid
+ confusion and potential name clashes the package is now known as
+ procps-ng (next generation), the version number was raised to 3.3.0
+ and the library so-name changed to libprocps.so
+
+What is being done to procps-ng at its new home?
+
+ All programs are in the process of being modernized, both in terms of
+ coding style and supporting documentation. Autotools have been
+ integrated and the library API has been expanded with many new fields
+ supported such as control groups, supplementary groups, etc. The top
+ program has been rewritten offering many new capabilities while
+ providing performance improvements up to 300%.
+
+Why does ps get signal 17?
+
+ No ps release has ever had this problem. Most likely your system has
+ been broken into. You might want to install a more recent version of
+ the OS. If you'd rather take your chances, simply upgrade procps.