| Ausführliche Beschreibung | Contains the header files and documentation for libbitmask
for use in developing applications that use the libbitmask library.
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This Bitmask library supports multi-word bitmask operations for
applications programmed in 'C'. It works in conjunction with recent
Linux kernel support for processor and memory placement on
multiprocessor SMP and NUMA systems. The cpuset library, being
developed in parallel, depends on this bitmask library.
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Bitmasks provide multi-word bit masks and operations thereon to do
such things as set and clear bits, intersect and union masks,
query bits, and display and parse masks.
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The initial intended use for these bitmasks is to represent sets of
CPUs and Memory Nodes, when configuring large SMP and NUMA systems.
However there is little in the semantics of bitmasks that is
specific to this particular use, and bitmasks should be usable for
other purposes that had similar design requirements.
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These bitmasks share the same underlying layout as the bitmasks
used by the Linux kernel to represent sets of CPUs and Memory
Nodes. Unlike the kernel bitmasks, these bitmasks use dynamically
allocated memory and are manipulated via a pointer. This enables a
program to work correctly on systems with various numbers of CPUs
and Nodes, without recompilation.
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There is a related cpuset library which uses the bitmask type
provided here to represent sets of CPUs and Memory Nodes. The
internal representation (as an array of unsigned longs, in little
endian order) is directly compatible with the sched_setaffinity(2)
and sched_getaffinity(2) system calls (added in Linux 2.6).
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