Revision 9d514262425691dddf942edea8bc9919e66fe140 authored by Wanpeng Li on 13 May 2015, 06:01:03 UTC, committed by Ingo Molnar on 19 June 2015, 08:06:46 UTC
This patch adds a check that prevents futile attempts to move DL tasks to a CPU with active tasks of equal or earlier deadline. The same behavior as commit 80e3d87b2c55 ("sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target") for rt class. Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431496867-4194-3-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent a6c0e74
argv_split.c
/*
* Helper function for splitting a string into an argv-like array.
*/
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/export.h>
static int count_argc(const char *str)
{
int count = 0;
bool was_space;
for (was_space = true; *str; str++) {
if (isspace(*str)) {
was_space = true;
} else if (was_space) {
was_space = false;
count++;
}
}
return count;
}
/**
* argv_free - free an argv
* @argv - the argument vector to be freed
*
* Frees an argv and the strings it points to.
*/
void argv_free(char **argv)
{
argv--;
kfree(argv[0]);
kfree(argv);
}
EXPORT_SYMBOL(argv_free);
/**
* argv_split - split a string at whitespace, returning an argv
* @gfp: the GFP mask used to allocate memory
* @str: the string to be split
* @argcp: returned argument count
*
* Returns an array of pointers to strings which are split out from
* @str. This is performed by strictly splitting on white-space; no
* quote processing is performed. Multiple whitespace characters are
* considered to be a single argument separator. The returned array
* is always NULL-terminated. Returns NULL on memory allocation
* failure.
*
* The source string at `str' may be undergoing concurrent alteration via
* userspace sysctl activity (at least). The argv_split() implementation
* attempts to handle this gracefully by taking a local copy to work on.
*/
char **argv_split(gfp_t gfp, const char *str, int *argcp)
{
char *argv_str;
bool was_space;
char **argv, **argv_ret;
int argc;
argv_str = kstrndup(str, KMALLOC_MAX_SIZE - 1, gfp);
if (!argv_str)
return NULL;
argc = count_argc(argv_str);
argv = kmalloc(sizeof(*argv) * (argc + 2), gfp);
if (!argv) {
kfree(argv_str);
return NULL;
}
*argv = argv_str;
argv_ret = ++argv;
for (was_space = true; *argv_str; argv_str++) {
if (isspace(*argv_str)) {
was_space = true;
*argv_str = 0;
} else if (was_space) {
was_space = false;
*argv++ = argv_str;
}
}
*argv = NULL;
if (argcp)
*argcp = argc;
return argv_ret;
}
EXPORT_SYMBOL(argv_split);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...