Jim Warner
f12c0d5c6e
top: minimize the statistics overhead for numa support
A recent libnuma potential corruption problem solution has caused me to reevaluate some associated numa logic for efficiency. Here is a summary of the problems that exist with current libnuma/user possible interactions: . Whenever the numa library was present extra overhead would always be incurred in maintaining the node stats even when the '2' or '3' commands were not being used. . As part of such overhead a separate loop was used to reinitialize each cpu/node structure with each display cycle so that prior accumulated totals were preserved. Again, it didn't matter if numa data was really shown. This commit attempts to refocus on the 'critical path' costs in a running top by optimizing for the occasions when numa node data is not being displayed. Under such conditions, no extra overhead will be incurred whether or not a distribution has the libnuma library present. To achieve this goal, some additional overhead will be incurred, but only when actually displaying numa data. And all such new costs have been minimized in spite of the gcc inclination to duplicate subscript resolution. Reference(s): commit 24bd950cb2e1722d459461f0f9c0c30a4b9ffdaa 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 distribution, please avoid causing troubles. This section applies to you. Avoid maintaining distribution specific patches. Send your patches to upstream, where they are at least reviewed, if not included. Please forward 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 without need for an account. For normal packages, ensure that you do not add debugging flags to the CFLAGS variable. UPSTREAM & BUG REPORTS procps-ng <procps@freelists.org>
Description
Command line and full screen utilities for browsing procfs, a "pseudo" file system dynamically generated by Linux to provide information about the status of entries in its process table.
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