[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [qemu-s390x] [PATCH v1] cpu-exec: fix missed CPU kick during interru
From: |
David Hildenbrand |
Subject: |
Re: [qemu-s390x] [PATCH v1] cpu-exec: fix missed CPU kick during interrupt injection |
Date: |
Mon, 11 Dec 2017 17:49:45 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 |
> atomic_mb_set can be a little faster on x86, so:
>
> diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
> index dfba5ebd29..4452cd9856 100644
> --- a/accel/tcg/cpu-exec.c
> +++ b/accel/tcg/cpu-exec.c
> @@ -528,12 +528,10 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
>
> /* Clear the interrupt flag now since we're processing
> * cpu->interrupt_request and cpu->exit_request.
> + * Ensure zeroing happens before reading cpu->exit_request or
> + * cpu->interrupt_request (see also smp_wmb in cpu_exit())
> */
> - atomic_set(&cpu->icount_decr.u16.high, 0);
> - /* Ensure zeroing happens before reading cpu->exit_request or
> - * cpu->interrupt_request. (also see cpu_exit())
> - */
> - smp_mb();
> + atomic_mb_set(&cpu->icount_decr.u16.high, 0);
>
> if (unlikely(atomic_read(&cpu->interrupt_request))) {
> int interrupt_request;
>
Looks good to me! Thanks!
--
Thanks,
David / dhildenb