[RFC PATCH 31/86] x86/thread_info: add TIF_NEED_RESCHED_LAZY

From: Ankur Arora
Date: Tue Nov 07 2023 - 17:03:13 EST


Add a new flag, TIF_NEED_RESCHED_LAZY which with TIF_NEED_RESCHED
gives the scheduler two levels of rescheduling priority:
TIF_NEED_RESCHED means that rescheduling happens at the next
opportunity; TIF_NEED_RESCHED_LAZY is used to note that a
reschedule is needed but does not impose any other constraints
on the scheduler.

Originally-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
---
arch/x86/include/asm/thread_info.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index d63b02940747..114d12120051 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -81,8 +81,9 @@ struct thread_info {
#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
-#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
-#define TIF_SSBD 5 /* Speculative store bypass disable */
+#define TIF_NEED_RESCHED_LAZY 4 /* Lazy rescheduling */
+#define TIF_SINGLESTEP 5 /* reenable singlestep on user return*/
+#define TIF_SSBD 6 /* Speculative store bypass disable */
#define TIF_SPEC_IB 9 /* Indirect branch speculation mitigation */
#define TIF_SPEC_L1D_FLUSH 10 /* Flush L1D on mm switches (processes) */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
@@ -104,6 +105,7 @@ struct thread_info {
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_SSBD (1 << TIF_SSBD)
#define _TIF_SPEC_IB (1 << TIF_SPEC_IB)
--
2.31.1