From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: [RFC PATCH 1/6] netback: page pool version 1
Date: Fri, 13 Jan 2012 12:37:46 -0500
Message-ID: <20120113173746.GA16182@phenom.dumpdata.com>
References: <1326473949-22389-1-git-send-email-wei.liu2@citrix.com>
 <1326473949-22389-2-git-send-email-wei.liu2@citrix.com>
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> +static idx_t free_head;
> +static int free_count;
> +static unsigned long pool_size;
> +static DEFINE_SPINLOCK(pool_lock);
> +static struct page_pool_entry *pool;
> +
> +static int get_free_entry(void)
> +{
> +	unsigned long flag;
> +	int idx;
> +
> +	spin_lock_irqsave(&pool_lock, flag);

What is the benfit of using the irq version of the spinlock instead
of the normal one??