Commit 476e8583 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched, x86: Enable Lazy preemption 



Add the TIF bit and select the Kconfig symbol to make it go.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/20241007075055.555778919@infradead.org
parent 35772d62

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -93,6 +93,7 @@ config X86 
	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS

	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE

	select ARCH_HAS_PMEM_API		if X86_64

	select ARCH_HAS_PREEMPT_LAZY

	select ARCH_HAS_PTE_DEVMAP		if X86_64

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_HW_PTE_YOUNG

arch/x86/include/asm/thread_info.h

+4 −2
Original line number Diff line number Diff line
@@ -87,8 +87,9 @@ 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	/* rescheduling necessary */

#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 */
@@ -110,6 +111,7 @@ 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)