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From: Jan Kara <jack@suse.cz>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Christoph Hellwig <hch@infradead.org>,
	Ingo Molnar <mingo@kernel.org>, Jan Kara <jack@suse.cz>,
	Jens Axboe <jens.axboe@oracle.com>
Subject: Re: [PATCH 08/11] smp: Move __smp_call_function_single() below its safe version
Date: Mon, 10 Feb 2014 21:29:11 +0100	[thread overview]
Message-ID: <20140210202911.GD16642@quack.suse.cz> (raw)
In-Reply-To: <1391876320-25068-9-git-send-email-fweisbec@gmail.com>

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@suse.cz>

								Honza
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Jens Axboe <jens.axboe@oracle.com>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> ---
>  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@suse.cz>
SUSE Labs, CR

  reply	other threads:[~2014-02-10 20:29 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-08 16:18 [RFC PATCH 00/11] smp: Single IPI cleanups Frederic Weisbecker
2014-02-08 16:18 ` [PATCH 01/11] block: Stop abusing csd.list for fifo_time Frederic Weisbecker
2014-02-08 16:18 ` [PATCH 02/11] block: Remove useless IPI struct initialization Frederic Weisbecker
2014-02-10 20:21   ` Jan Kara
2014-02-08 16:18 ` [PATCH 03/11] block: Stop abusing rq->csd.list in blk-softirq Frederic Weisbecker
2014-02-08 16:18 ` [PATCH 04/11] smp: Iterate functions through llist_for_each_entry_safe() Frederic Weisbecker
2014-02-08 16:18 ` [PATCH 05/11] smp: Remove unused list_head from csd Frederic Weisbecker
2014-02-08 16:18 ` [PATCH 06/11] smp: Teach __smp_call_function_single() to check for offline cpus Frederic Weisbecker
2014-02-08 16:18 ` [PATCH 07/11] smp: Consolidate the various smp_call_function_single() declensions Frederic Weisbecker
2014-02-10 20:27   ` Jan Kara
2014-02-08 16:18 ` [PATCH 08/11] smp: Move __smp_call_function_single() below its safe version Frederic Weisbecker
2014-02-10 20:29   ` Jan Kara [this message]
2014-02-08 16:18 ` [PATCH 09/11] watchdog: Simplify a little the IPI call Frederic Weisbecker
2014-02-10 12:26   ` Michal Hocko
2014-02-10 14:46   ` Don Zickus
2014-02-08 16:18 ` [PATCH 10/11] smp: Remove wait argument from __smp_call_function_single() Frederic Weisbecker
2014-02-08 16:42   ` Christoph Hellwig
2014-02-08 16:46     ` Frederic Weisbecker
2014-02-08 16:54       ` Christoph Hellwig
2014-02-08 16:18 ` [PATCH 11/11] smp: Enhance and precise the role & requirements of __smp_call_function_single() Frederic Weisbecker
  -- strict thread matches above, loose matches on Subject: below --
2014-02-24 15:39 [PATCH 00/11] smp: Single IPI cleanups v2 Frederic Weisbecker
2014-02-24 15:39 ` [PATCH 08/11] smp: Move __smp_call_function_single() below its safe version Frederic Weisbecker

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