Both the sysfs and procfs parsing (through GET_NPROCS_PARSER) are
removed in favor the syscall. The initial scratch buffer should
fit to most of the common usage (1024 bytes with maps to 8192 CPUs).
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
And replace the generic algorithm with the Brian Kernighan's one.
GCC optimize it with popcnt if the architecture supports, so there
is no need to add the extra POPCNT define to enable it.
This is really a micro-optimization that only adds complexity:
recent ABIs already support it (x86-64-v2 or power64le) and it
simplifies the code for internal usage, since i686 does not allow an
internal iFUNC call.
Checked on x86_64-linux-gnu, aarch64-linux-gnu, and
powerpc64le-linux-gnu.
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
posix/sched_cpucount.c assumes that size of __cpu_mask == size of long,
which is incorrect for x32. This patch uses __builtin_popcount, which
is availabe in GCC 4.9, in posix/sched_cpucount.c.
Tested on i686, x86-64 and x32 with multi-arch disabled.
[BZ #21696]
* posix/sched_cpucount.c: Don't include <limits.h>.
(__sched_cpucount): Use __builtin_popcount.
(tests): Add tst-cpucount.
* posix/sched_cpucount.c: New file.
* posix/tst-cpucount.c: New file.
* posix/Versions: Export __sched_cpucount with version GLIBC_2.6.
