82 lines
2.9 KiB
C
82 lines
2.9 KiB
C
|
/****************************************************************************
|
||
|
|
* libc/sched/sched_cpucount.c
|
||
|
|
*
|
||
|
|
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
|
||
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions
|
||
|
|
* are met:
|
||
|
|
*
|
||
|
|
* 1. Redistributions of source code must retain the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer.
|
||
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer in
|
||
|
|
* the documentation and/or other materials provided with the
|
||
|
|
* distribution.
|
||
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
||
|
|
* used to endorse or promote products derived from this software
|
||
|
|
* without specific prior written permission.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
||
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
||
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
||
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
||
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
||
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
*
|
||
|
|
****************************************************************************/
|
||
|
|
|
||
|
|
/****************************************************************************
|
||
|
|
* Included Files
|
||
|
|
****************************************************************************/
|
||
|
|
|
||
|
|
#include <nuttx/config.h>
|
||
|
|
|
||
|
|
#include <sched.h>
|
||
|
|
|
||
|
|
#ifdef CONFIG_SMP
|
||
|
|
|
||
|
|
/****************************************************************************
|
||
|
|
* Public Functions
|
||
|
|
****************************************************************************/
|
||
|
|
|
||
|
|
/****************************************************************************
|
||
|
|
* Name: sched_cpu_count
|
||
|
|
*
|
||
|
|
* Description:
|
||
|
|
* Return the number of bits set in the 'set'. This could be improved by
|
||
|
|
* using CPU-specific bit counting instructions.
|
||
|
|
*
|
||
|
|
* Inputs:
|
||
|
|
* set - The set of CPUs to be counted.
|
||
|
|
*
|
||
|
|
* Return Value:
|
||
|
|
* The number of CPUs in 'set'
|
||
|
|
*
|
||
|
|
****************************************************************************/
|
||
|
|
|
||
|
|
int sched_cpu_count(FAR const cpu_set_t *set);
|
||
|
|
{
|
||
|
|
int count;
|
||
|
|
int cpu;
|
||
|
|
|
||
|
|
for (cpu = 0, count = 0; cpu < CONFIG_SMP_NCPUS; cpu++)
|
||
|
|
{
|
||
|
|
if ((*set & (1 << cpu)) != 0)
|
||
|
|
{
|
||
|
|
count++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* CONFIG_SMP */
|