On Thu, Jul 11, 2013 at 01:25:39PM +0800, Miao Xie wrote:
> It is unnecessary to unlock the extent by the page size, we can do it
> in batches, it makes the random read be faster by ~6%.
>
> Signed-off-by: Miao Xie <miaox@xxxxxxxxxxxxxx>
> ---
> fs/btrfs/extent_io.c | 70 ++++++++++++++++++++++++++++++----------------------
> 1 file changed, 40 insertions(+), 30 deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 9f4dedf..8f95418 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -762,15 +762,6 @@ static void cache_state(struct extent_state *state,
> }
> }
>
> -static void uncache_state(struct extent_state **cached_ptr)
> -{
> - if (cached_ptr && (*cached_ptr)) {
> - struct extent_state *state = *cached_ptr;
> - *cached_ptr = NULL;
> - free_extent_state(state);
> - }
> -}
> -
> /*
> * set some bits on a range in the tree. This may require allocations or
> * sleeping, so the gfp mask is used to indicate what is allowed.
> @@ -2395,6 +2386,18 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
> bio_put(bio);
> }
>
> +static void
> +endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
> + int uptodate)
> +{
> + struct extent_state *cached = NULL;
> + u64 end = start + len - 1;
> +
> + if (uptodate && tree->track_uptodate)
> + set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC);
> + unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
> +}
> +
> /*
> * after a readpage IO is done, we need to:
> * clear the uptodate bits on error
> @@ -2417,6 +2420,8 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
> u64 start;
> u64 end;
> u64 len;
> + u64 extent_start = 0;
> + u64 extent_len = 0;
> int mirror;
> int ret;
>
> @@ -2425,8 +2430,6 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
>
> do {
> struct page *page = bvec->bv_page;
> - struct extent_state *cached = NULL;
> - struct extent_state *state;
> struct inode *inode = page->mapping->host;
>
> pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
> @@ -2452,17 +2455,6 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
> if (++bvec <= bvec_end)
> prefetchw(&bvec->bv_page->flags);
>
> - spin_lock(&tree->lock);
> - state = find_first_extent_bit_state(tree, start, EXTENT_LOCKED);
> - if (likely(state && state->start == start)) {
> - /*
> - * take a reference on the state, unlock will drop
> - * the ref
> - */
> - cache_state(state, &cached);
> - }
> - spin_unlock(&tree->lock);
> -
> mirror = io_bio->mirror_num;
> if (likely(uptodate && tree->ops &&
> tree->ops->readpage_end_io_hook)) {
> @@ -2501,18 +2493,11 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
> test_bit(BIO_UPTODATE, &bio->bi_flags);
> if (err)
> uptodate = 0;
> - uncache_state(&cached);
> continue;
> }
> }
> readpage_ok:
> - if (uptodate && tree->track_uptodate) {
> - set_extent_uptodate(tree, start, end, &cached,
> - GFP_ATOMIC);
> - }
> - unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
> -
> - if (uptodate) {
> + if (likely(uptodate)) {
> loff_t i_size = i_size_read(inode);
> pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
> unsigned offset;
> @@ -2528,8 +2513,33 @@ readpage_ok:
> }
> unlock_page(page);
> offset += len;
> +
> + if (unlikely(!uptodate)) {
> + if (extent_len) {
> + endio_readpage_release_extent(tree,
> + extent_start,
> + extent_len, 1);
> + extent_start = 0;
> + extent_len = 0;
> + }
> + endio_readpage_release_extent(tree, start,
> + end - start + 1, 0);
> + } else if (!extent_len) {
> + extent_start = start;
> + extent_len = end + 1 - start;
> + } else if (extent_start + extent_len == start) {
> + extent_len += end + 1 - start;
> + } else {
> + endio_readpage_release_extent(tree, extent_start,
> + extent_len, uptodate);
> + extent_start = start;
> + extent_len = end + 1 - start;
> + }
> } while (bvec <= bvec_end);
>
> + if (extent_len)
> + endio_readpage_release_extent(tree, extent_start, extent_len,
> + uptodate);
> if (io_bio->end_io)
> io_bio->end_io(io_bio, err);
> bio_put(bio);
This patch is causing xfstest btrfs/265 to blow up, I'm kicking this series out
until you fix it. Thanks,
Josef
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