From a6c372de6e4b9a8188b66badcee3e3792eccdd26 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 12 Jun 2009 22:27:01 -0600 Subject: [PATCH] lguest: fix lguest wake on guest clock tick, or fd activity The Launcher could be inside the Guest on another CPU; wake_up_process will do nothing because it is "running". kick_process will knock it back into our kernel in this case, otherwise we'll miss it until the next guest exit. Signed-off-by: Rusty Russell --- drivers/lguest/interrupts_and_traps.c | 6 +++--- drivers/lguest/lguest_user.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index 6e99adbe1946..9ea26ad88c9d 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -511,9 +511,9 @@ static enum hrtimer_restart clockdev_fn(struct hrtimer *timer) /* Remember the first interrupt is the timer interrupt. */ set_bit(0, cpu->irqs_pending); - /* If the Guest is actually stopped, we need to wake it up. */ - if (cpu->halted) - wake_up_process(cpu->tsk); + /* Guest may be stopped or running on another CPU. */ + if (!wake_up_process(cpu->tsk)) + kick_process(cpu->tsk); return HRTIMER_NORESTART; } diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c index b8ee103eed5f..bcdcf3453e78 100644 --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lguest_user.c @@ -24,8 +24,8 @@ static int break_guest_out(struct lg_cpu *cpu, const unsigned long __user*input) if (on) { cpu->break_out = 1; - /* Pop it out of the Guest (may be running on different CPU) */ - wake_up_process(cpu->tsk); + if (!wake_up_process(cpu->tsk)) + kick_process(cpu->tsk); /* Wait for them to reset it */ return wait_event_interruptible(cpu->break_wq, !cpu->break_out); } else { -- 2.20.1