sched/isolation: Add basic isolcpus flags

Add flags to control NOHZ and domain isolation from "isolcpus=", in order to centralize the isolation features to a common interface. Domain isolation remains the default so not to break the existing isolcpus boot paramater behaviour. Further flags in the future may include 0hz (1hz tick offload) and timers, workqueue, RCU, kthread, watchdog, likely all merged together in a common flag ("async"?). In any case, this will have to be modifiable by cpusets.

Frederic Weisbecker committed 9 years ago

Commit 150dfee1 parent edb93821 file · +25 −1Browse files

Unified · Split

kernel/sched/isolation.c+25−1

@@ -11,6 +11,7 @@ · 10 unmodified lines
11	#include <linux/init.h>	11	#include <linux/init.h>
12	#include <linux/kernel.h>	12	#include <linux/kernel.h>
13	#include <linux/static_key.h>	13	#include <linux/static_key.h>
		14	#include <linux/ctype.h>
14		15
15	DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);	16	DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
16	EXPORT_SYMBOL_GPL(housekeeping_overriden);	17	EXPORT_SYMBOL_GPL(housekeeping_overriden);
@@ -126,6 +127,29 @@ __setup("nohz_full=", housekeeping_nohz_full_setup); · 109 unmodified lines
126		127
127	static int __init housekeeping_isolcpus_setup(char *str)	128	static int __init housekeeping_isolcpus_setup(char *str)
128	{	129	{
129	return housekeeping_setup(str, HK_FLAG_DOMAIN);	130	unsigned int flags = 0;
		131
		132	while (isalpha(*str)) {
		133	if (!strncmp(str, "nohz,", 5)) {
		134	str += 5;
		135	flags \|= HK_FLAG_TICK;
		136	continue;
		137	}
		138
		139	if (!strncmp(str, "domain,", 7)) {
		140	str += 7;
		141	flags \|= HK_FLAG_DOMAIN;
		142	continue;
		143	}
		144
		145	pr_warn("isolcpus: Error, unknown flag\n");
		146	return 0;
		147	}
		148
		149	/* Default behaviour for isolcpus without flags */
		150	if (!flags)
		151	flags \|= HK_FLAG_DOMAIN;
		152
		153	return housekeeping_setup(str, flags);
130	}	154	}
131	__setup("isolcpus=", housekeeping_isolcpus_setup);	155	__setup("isolcpus=", housekeeping_isolcpus_setup);