From 26baa1f1c4bdc34b8d698c1900b407d863ad0e69 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 4 Oct 2024 14:47:02 +0200 Subject: sched: Add TIF_NEED_RESCHED_LAZY infrastructure Add the basic infrastructure to split the TIF_NEED_RESCHED bit in two. Either bit will cause a resched on return-to-user, but only TIF_NEED_RESCHED will drive IRQ preemption. No behavioural change intended. Suggested-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Sebastian Andrzej Siewior Link: https://lkml.kernel.org/r/20241007075055.219540785@infradead.org --- kernel/entry/common.c | 2 +- kernel/entry/kvm.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/entry') diff --git a/kernel/entry/common.c b/kernel/entry/common.c index 5b6934e23c21..e33691d5adf7 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -98,7 +98,7 @@ __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs, local_irq_enable_exit_to_user(ti_work); - if (ti_work & _TIF_NEED_RESCHED) + if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)) schedule(); if (ti_work & _TIF_UPROBE) diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c index 2e0f75bcb7fd..8485f63863af 100644 --- a/kernel/entry/kvm.c +++ b/kernel/entry/kvm.c @@ -13,7 +13,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work) return -EINTR; } - if (ti_work & _TIF_NEED_RESCHED) + if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)) schedule(); if (ti_work & _TIF_NOTIFY_RESUME) @@ -24,7 +24,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work) return ret; ti_work = read_thread_flags(); - } while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched()); + } while (ti_work & XFER_TO_GUEST_MODE_WORK); return 0; } -- cgit v1.2.3