Commit-ID: 150dfee95feb913876ced5cc559a342384e8ea97
Gitweb: https://git.kernel.org/tip/150dfee95feb913876ced5cc559a342384e8ea97
Author: Frederic Weisbecker <[email protected]>
AuthorDate: Fri, 27 Oct 2017 04:42:38 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 27 Oct 2017 09:55:31 +0200
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.
Signed-off-by: Frederic Weisbecker <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luiz Capitulino <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Wanpeng Li <[email protected]>
Link:
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[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);
