Re: [PATCH 08/11] smp: Move __smp_call_function_single() below itssafe version

From: Jan Kara
Date: Mon Feb 10 2014 - 15:29:20 EST


On Sat 08-02-14 17:18:37, Frederic Weisbecker wrote:
> Move this function closer to __smp_call_function_single(). These functions
> have very similar behavior and should be displayed in the same block
> for clarity.
Whatever :). You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza
>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Jan Kara <jack@xxxxxxx>
> Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> ---
> kernel/smp.c | 64 ++++++++++++++++++++++++++++++------------------------------
> 1 file changed, 32 insertions(+), 32 deletions(-)
>
> diff --git a/kernel/smp.c b/kernel/smp.c
> index 64bb0d4..fa04ab9 100644
> --- a/kernel/smp.c
> +++ b/kernel/smp.c
> @@ -237,6 +237,38 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
> }
> EXPORT_SYMBOL(smp_call_function_single);
>
> +/**
> + * __smp_call_function_single(): Run a function on a specific CPU
> + * @cpu: The CPU to run on.
> + * @csd: Pre-allocated and setup data structure
> + * @wait: If true, wait until function has completed on specified CPU.
> + *
> + * Like smp_call_function_single(), but allow caller to pass in a
> + * pre-allocated data structure. Useful for embedding @data inside
> + * other structures, for instance.
> + */
> +int __smp_call_function_single(int cpu, struct call_single_data *csd, int wait)
> +{
> + int err = 0;
> + int this_cpu;
> +
> + this_cpu = get_cpu();
> + /*
> + * Can deadlock when called with interrupts disabled.
> + * We allow cpu's that are not yet online though, as no one else can
> + * send smp call function interrupt to this cpu and as such deadlocks
> + * can't happen.
> + */
> + WARN_ON_ONCE(cpu_online(this_cpu) && wait && irqs_disabled()
> + && !oops_in_progress);
> +
> + err = generic_exec_single(cpu, csd, csd->func, csd->info, wait);
> + put_cpu();
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(__smp_call_function_single);
> +
> /*
> * smp_call_function_any - Run a function on any of the given cpus
> * @mask: The mask of cpus it can run on.
> @@ -281,38 +313,6 @@ call:
> EXPORT_SYMBOL_GPL(smp_call_function_any);
>
> /**
> - * __smp_call_function_single(): Run a function on a specific CPU
> - * @cpu: The CPU to run on.
> - * @csd: Pre-allocated and setup data structure
> - * @wait: If true, wait until function has completed on specified CPU.
> - *
> - * Like smp_call_function_single(), but allow caller to pass in a
> - * pre-allocated data structure. Useful for embedding @data inside
> - * other structures, for instance.
> - */
> -int __smp_call_function_single(int cpu, struct call_single_data *csd, int wait)
> -{
> - int err = 0;
> - int this_cpu;
> -
> - this_cpu = get_cpu();
> - /*
> - * Can deadlock when called with interrupts disabled.
> - * We allow cpu's that are not yet online though, as no one else can
> - * send smp call function interrupt to this cpu and as such deadlocks
> - * can't happen.
> - */
> - WARN_ON_ONCE(cpu_online(this_cpu) && wait && irqs_disabled()
> - && !oops_in_progress);
> -
> - err = generic_exec_single(cpu, csd, csd->func, csd->info, wait);
> - put_cpu();
> -
> - return err;
> -}
> -EXPORT_SYMBOL_GPL(__smp_call_function_single);
> -
> -/**
> * smp_call_function_many(): Run a function on a set of other CPUs.
> * @mask: The set of cpus to run on (only runs on online subset).
> * @func: The function to run. This must be fast and non-blocking.
> --
> 1.8.3.1
>
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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