diff options
author | Henning Heinold <heinold@inf.fu-berlin.de> | 2011-06-04 21:21:41 +0200 |
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committer | Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> | 2011-11-07 20:57:02 +0100 |
commit | 19dd090a0f68765db87990ef8eda9bf77bb29581 (patch) | |
tree | f210bb330d8b3dda2bcc345a80ce476bd41e1a69 /libc/sysdeps/linux/common/sched_cpucount.c | |
parent | 0c7690f6a5d6e073052ee6487f768289db3a58f7 (diff) |
libc: flesh out linux scheduler functions
Most stuff was taken from the eglibc.
Signed-off-by: Henning Heinold <heinold@inf.fu-berlin.de>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Diffstat (limited to 'libc/sysdeps/linux/common/sched_cpucount.c')
-rw-r--r-- | libc/sysdeps/linux/common/sched_cpucount.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/sched_cpucount.c b/libc/sysdeps/linux/common/sched_cpucount.c new file mode 100644 index 000000000..331c0b8df --- /dev/null +++ b/libc/sysdeps/linux/common/sched_cpucount.c @@ -0,0 +1,60 @@ +/* Copyright (C) 2007 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <limits.h> +#include <sched.h> + + +int +__sched_cpucount (size_t setsize, const cpu_set_t *setp) +{ + int s = 0; + const __cpu_mask *p = setp->__bits; + const __cpu_mask *end = &setp->__bits[setsize / sizeof (__cpu_mask)]; + + while (p < end) + { + __cpu_mask l = *p++; + +#ifdef POPCNT + s += POPCNT (l); +#else + if (l == 0) + continue; + +# if LONG_BIT > 32 + l = (l & 0x5555555555555555ul) + ((l >> 1) & 0x5555555555555555ul); + l = (l & 0x3333333333333333ul) + ((l >> 2) & 0x3333333333333333ul); + l = (l & 0x0f0f0f0f0f0f0f0ful) + ((l >> 4) & 0x0f0f0f0f0f0f0f0ful); + l = (l & 0x00ff00ff00ff00fful) + ((l >> 8) & 0x00ff00ff00ff00fful); + l = (l & 0x0000ffff0000fffful) + ((l >> 16) & 0x0000ffff0000fffful); + l = (l & 0x00000000fffffffful) + ((l >> 32) & 0x00000000fffffffful); +# else + l = (l & 0x55555555ul) + ((l >> 1) & 0x55555555ul); + l = (l & 0x33333333ul) + ((l >> 2) & 0x33333333ul); + l = (l & 0x0f0f0f0ful) + ((l >> 4) & 0x0f0f0f0ful); + l = (l & 0x00ff00fful) + ((l >> 8) & 0x00ff00fful); + l = (l & 0x0000fffful) + ((l >> 16) & 0x0000fffful); +# endif + + s += l; +#endif + } + + return s; +} |