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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2008-11-13 17:47:56 -0500 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2008-11-25 20:53:58 -0500 |
| commit | b62e3548228be55c9b46f4b26f90a7065cd05090 (patch) | |
| tree | bfb9947a20026a11d3e4f40b3508af1b46d4d16a /man3 | |
| parent | d69305f69181ebed1bf207499d4a273bb88a0348 (diff) | |
| download | man-pages-b62e3548228be55c9b46f4b26f90a7065cd05090.tar.gz | |
CPU_SET.3: Document CPU_ALLOC()/CPU_ALLOC_SIZE() bug
These macros return twice what they should because of thinko
in glibc 2.8 and earlier. The bug is fixed for glibc 2.9.
http://sourceware.org/bugzilla/show_bug.cgi?id=7029
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Diffstat (limited to 'man3')
| -rw-r--r-- | man3/CPU_SET.3 | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/man3/CPU_SET.3 b/man3/CPU_SET.3 index 90b85da79a..7046fde3de 100644 --- a/man3/CPU_SET.3 +++ b/man3/CPU_SET.3 @@ -177,12 +177,6 @@ in the range 0 to Return the size in bytes of the CPU set that would be needed to hold CPUs in the range 0 to .IR num_cpus-1 . -.\" FIXME . track this bug -.\" Currently (glibc 2.8), CPU_ALLOC_SIZE() returns double the -.\" value that it should. This also causes CPU_ALLOC() to allocate -.\" twice as much memory as is required. -.\" http://sourceware.org/bugzilla/show_bug.cgi?id=7029 -.\" Eventually, write this up in BUGS. This macro provides the value that can be used for .I setsize in the @@ -305,6 +299,17 @@ main(int argc, char *argv[]) exit(EXIT_SUCCESS); } .fi +.SH BUGS +On 32-bit platforms with glibc 2.8 and earlier, +.BR CPU_ALLOC () +allocates twice as much space as is required, and +.BR CPU_ALLOC_SIZE () +returns a value twice as large as it should. +The only consequences for most programs is wasted space, +and slightly less efficient operation of the macros that +operate on dynamically allocated CPU sets. +These bugs are fixed in glibc 2.9. +.\" http://sourceware.org/bugzilla/show_bug.cgi?id=7029 .SH "SEE ALSO" .BR sched_setaffinity (2), .BR pthread_attr_setaffinity_np (3), |