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Re: [Qemu-devel] [PATCH 12/16] cpus-common: remove redundant call to exc
From: |
Alex Bennée |
Subject: |
Re: [Qemu-devel] [PATCH 12/16] cpus-common: remove redundant call to exclusive_idle() |
Date: |
Mon, 26 Sep 2016 09:25:36 +0100 |
User-agent: |
mu4e 0.9.17; emacs 25.1.50.1 |
Paolo Bonzini <address@hidden> writes:
> No need to call exclusive_idle() from cpu_exec_end since it is done
> immediately afterwards in cpu_exec_start. Any exclusive section could
> run as soon as cpu_exec_end leaves, because cpu->running is false and the
> mutex is not taken, so the call does not add any protection either.
>
> Signed-off-by: Paolo Bonzini <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
> ---
> cpus-common.c | 1 -
> docs/tcg-exclusive.promela | 1 -
> 2 files changed, 2 deletions(-)
>
> diff --git a/cpus-common.c b/cpus-common.c
> index 115f3d4..80aaf9b 100644
> --- a/cpus-common.c
> +++ b/cpus-common.c
> @@ -221,7 +221,6 @@ void cpu_exec_end(CPUState *cpu)
> qemu_cond_signal(&exclusive_cond);
> }
> }
> - exclusive_idle();
> qemu_mutex_unlock(&qemu_cpu_list_lock);
> }
>
> diff --git a/docs/tcg-exclusive.promela b/docs/tcg-exclusive.promela
> index 360edcd..9e7d9e3 100644
> --- a/docs/tcg-exclusive.promela
> +++ b/docs/tcg-exclusive.promela
> @@ -123,7 +123,6 @@ byte has_waiter[N_CPUS];
> }
> \
> :: else -> skip;
> \
> fi;
> \
> - exclusive_idle();
> \
> MUTEX_UNLOCK(mutex);
>
> // Promela processes
--
Alex Bennée
- Re: [Qemu-devel] [PATCH 14/16] cpus-common: Introduce async_safe_run_on_cpu(), (continued)
- [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Paolo Bonzini, 2016/09/23
- Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Richard Henderson, 2016/09/23
- Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Paolo Bonzini, 2016/09/24
- Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Richard Henderson, 2016/09/24
- Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Paolo Bonzini, 2016/09/26
- Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Alex Bennée, 2016/09/26
- Re: [Qemu-devel] [PATCH 16/16] cpus-common: lock-free fast path for cpu_exec_start/end, Paolo Bonzini, 2016/09/26
[Qemu-devel] [PATCH 12/16] cpus-common: remove redundant call to exclusive_idle(), Paolo Bonzini, 2016/09/23
Re: [Qemu-devel] [PATCH v8 00/16] cpu-exec: Safe work in quiescent state, Alex Bennée, 2016/09/25