Re: [RFC v4 03/15] vfs,hot_track: add the function for collecting I/O frequency

[Zheng Liu <gnehzuil.liu@gmail.com>]

Hi Zhiyong, 

On Thu, Oct 25, 2012 at 11:08:55PM +0800, zwu.kernel@gmail.com wrote:
[snip]
> @@ -199,6 +342,54 @@ err:
>  }
>  
>  /*
> + * Main function to update access frequency from read/writepage(s) hooks
> + */
> +inline void hot_update_freqs(struct inode *inode, u64 start,
> +			u64 len, int rw)

This function seems too big.  So we really need to inline this function?

Regards,
Zheng

> +{
> +	struct hot_info *root = inode->i_sb->s_hot_root;
> +	struct hot_inode_item *he;
> +	struct hot_range_item *hr;
> +	u32 cur, end;
> +
> +	if (!root || (len == 0))
> +		return;
> +
> +	he = hot_inode_item_find(root, inode->i_ino);
> +	if (IS_ERR(he)) {
> +		WARN_ON(1);
> +		return;
> +	}
> +
> +	spin_lock(&he->hot_inode.lock);
> +	hot_freq_data_update(&he->hot_inode.hot_freq_data, rw);
> +	spin_unlock(&he->hot_inode.lock);
> +
> +	/*
> +	 * Align ranges on RANGE_SIZE boundary
> +	 * to prevent proliferation of range structs
> +	 */
> +	end = (start + len + RANGE_SIZE - 1) >> RANGE_BITS;
> +	for (cur = (start >> RANGE_BITS); cur < end; cur++) {
> +		hr = hot_range_item_find(he, cur);
> +		if (IS_ERR(hr)) {
> +			WARN_ON(1);
> +			hot_inode_item_put(he);
> +			return;
> +		}
> +
> +		spin_lock(&hr->hot_range.lock);
> +		hot_freq_data_update(&hr->hot_range.hot_freq_data, rw);
> +		spin_unlock(&hr->hot_range.lock);
> +
> +		hot_range_item_put(hr);
> +	}
> +
> +	hot_inode_item_put(he);
> +}
> +EXPORT_SYMBOL_GPL(hot_update_freqs);