da06b8fa59
A recent commit eliminated the potential for a storage
violation with forest view mode. It occurred when some
program (erroneously?) created a lengthy forking loop.
However, the associated commit message was misleading.
The message implied that an unexpected order following
a sort on start_time was the cause of storage overruns
and a 'char' used to track nesting level only distorts
the display when it goes negative. Actually, the truth
is really just the opposite. Any start_time sort quirk
causes no harm while that 'char' can yield corruption.
Should some child end up sorted ahead of its parent by
way of an extremely unlikely shared start_time the end
result is such a child will be displayed unnested just
like init or kthreadd along with all its own children.
However, if nesting levels exceeded 255 (and became 0)
a massive array overrun could be triggered when such a
task and *all* its children were added to an array for
the second time. Exactly how much storage was violated
depended on the number of children that zeroed process
had spawned (hinted at via either SIGSEGV or SIGABRT).
The earlier commit limited nested levels to 100 so the
root cause of the storage violation was already fixed.
The potential for distorted nesting levels due to sort
on start_time would seem to remain. But it's extremely
unlikely that 2 tasks would share the same start_time.
Even so, a new #define has been introduced which makes
top impervious to the order of tasks such that a qsort
is no longer necessary (providing an init/systemd task
exists & was harvested as the first task by readproc).
It can be utilized if distorted nesting ever becomes a
real issue. But since there is a 5-10% performance hit
with that, we'll continue using start_time as default.
References(s):
commit ce70017eb1
Signed-off-by: Jim Warner <james.warner@comcast.net>
COMPATIBILITY
This code is intended for use with Linux 2.6.xx, 3.x and
hopefully all future kernels.
INSTALLATION
If you are using git version of the project you need extra step.
./autogen.sh
After that, and everyone using .tar.xz version of procps-ng, can
do normal build. Read './configure --help' to select options for
your needs.
./configure
make
make install
If you have DejaGNU installed you can run optional test suite.
make check
HOW TO CONTRIBUTE
See Documentation/BUGS file.
PACKAGING
If you are a downstream maintainer (packager) for a Linux
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Avoid maintaining distribution specific patches. Send your
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Please forward bug reports. If your bug database is public and
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TRANSLATING MAN PAGES
There is a three-step process for translating man pages. Most
of the work happens in the man-po directory.
make -C man-po translate-templates
Creates the translation templates (the .pot files) for translators
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make get-trans
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make -C man-po translate-mans
This is also called in the dist-hook and is where the translation
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All of the man pages generated are found in
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UPSTREAM & BUG REPORTS
procps-ng <procps@freelists.org>