Add flags to control nohz and domain isolations 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.
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: Luiz Capitulino <[email protected]>
---
kernel/sched/isolation.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 8f666bc..b71b436 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/static_key.h>
+#include <linux/ctype.h>
DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
EXPORT_SYMBOL_GPL(housekeeping_overriden);
@@ -126,6 +127,29 @@ __setup("nohz_full=", housekeeping_nohz_full_setup);
static int __init housekeeping_isolcpus_setup(char *str)
{
- return housekeeping_setup(str, HK_FLAG_DOMAIN);
+ unsigned int flags = 0;
+
+ while (isalpha(*str)) {
+ if (!strncmp(str, "nohz,", 5)) {
+ str += 5;
+ flags |= HK_FLAG_TICK;
+ continue;
+ }
+
+ if (!strncmp(str, "domain,", 7)) {
+ str += 7;
+ flags |= HK_FLAG_DOMAIN;
+ continue;
+ }
+
+ pr_warn("isolcpus: Error, unknown flag\n");
+ return 0;
+ }
+
+ /* Default behaviour for isolcpus without flags */
+ if (!flags)
+ flags |= HK_FLAG_DOMAIN;
+
+ return housekeeping_setup(str, flags);
}
__setup("isolcpus=", housekeeping_isolcpus_setup);
--
2.7.4
