nohz_full is a feature that only fits into rare and very corner cases.
Yet distros enable it by default and therefore the related fields are
always reserved in the task struct.
Those task fields are stored in the middle of cacheline hot places such
as cputime accounting and context switch counting, which doesn't make
any sense for a feature that is disabled most of the time.
Move the nohz_full storage to colder places.
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
---
include/linux/sched.h | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 9632e3318e0d..10a9aa41b43a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1088,13 +1088,7 @@ struct task_struct {
#endif
u64 gtime;
struct prev_cputime prev_cputime;
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
- struct vtime vtime;
-#endif
-#ifdef CONFIG_NO_HZ_FULL
- atomic_t tick_dep_mask;
-#endif
/* Context switch counts: */
unsigned long nvcsw;
unsigned long nivcsw;
@@ -1411,6 +1405,14 @@ struct task_struct {
struct task_delay_info *delays;
#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+ struct vtime vtime;
+#endif
+
+#ifdef CONFIG_NO_HZ_FULL
+ atomic_t tick_dep_mask;
+#endif
+
#ifdef CONFIG_FAULT_INJECTION
int make_it_fail;
unsigned int fail_nth;
--
2.46.0
