On Wed, May 18, 2011 at 1:17 PM, Prasad Joshi <prasadjoshi...@gmail.com> wrote:
> QCOW uses two tables level1 (L1) table and level2
> (L2) table. The L1 table points to offset of L2
> table. When a QCOW image is probed, the L1 table is
> cached in the memory to avoid reading it from disk
> on every reference. This caching imporves the
> performance. The similar performance improvment can
> be observed when L2 tables are also cached. It is
> impossible to cache all of the L2 tables because of
> the memory constraint. The patch adds L2 table
> caching capability for upto 128 L2 tables, it uses
> combination of RB tree and List to manage the L2
> cached tables. The link list implementation helps
> in building simple LRU structure and RB tree helps
> in improving the search time during read/write
> operations.
Can you please split that text into more readable paragraphs? The line
wrapping column seems rather aggressive that's also contributing to
unreadability.
> @@ -16,6 +16,153 @@
> #include <linux/kernel.h>
> #include <linux/types.h>
>
> +static inline int insert(struct rb_root *root, struct qcow_l2_cache *new)
> +{
> + struct rb_node **link = &(root->rb_node), *parent = NULL;
> + u64 offset = new->offset;
> +
> + /* search the tree */
> + while (*link) {
> + struct qcow_l2_cache *t;
> +
> + t = rb_entry(*link, struct qcow_l2_cache, node);
> + if (!t)
> + goto error;
> +
[snip, snip]
This function and others are way to big to be marked as "inline".
Pekka
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