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Message-ID: <84144f020802030253y596ca557w3a44a8601a13596d@mail.gmail.com>
Date: Sun, 3 Feb 2008 12:53:02 +0200
From: "Pekka Enberg" <penberg@cs.helsinki.fi>
To: "Nick Piggin" <npiggin@suse.de>
Subject: Re: [rfc] direct IO submission and completion scalability issues
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>,
       linux-kernel@vger.kernel.org, arjan@linux.intel.com, mingo@elte.hu,
       ak@suse.de, jens.axboe@oracle.com, James.Bottomley@steeleye.com,
       andrea@suse.de, clameter@sgi.com, akpm@linux-foundation.org,
       andrew.vasquez@qlogic.com, willy@linux.intel.com,
       "Zach Brown" <zach.brown@oracle.com>
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	 <20080203095252.GA11043@wotan.suse.de>
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Hi Nick,

On Feb 3, 2008 11:52 AM, Nick Piggin <npiggin@suse.de> wrote:
> +asmlinkage void smp_call_function_fast_interrupt(void)
> +{

[snip]

> +       while (!list_empty(&list)) {
> +               struct call_single_data *data;
> +
> +               data = list_entry(list.next, struct call_single_data, list);
> +               list_del(&data->list);
> +
> +               data->func(data->info);
> +               if (data->wait) {
> +                       smp_mb();
> +                       data->wait = 0;

Why do we need smp_mb() here (maybe add a comment to keep
Andrew/checkpatch happy)?

                        Pekka
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