On May. 10, 2010, 6:36 +0300, Zhang Jingwang <zhangjingwang@xxxxxxxxxxxx> wrote:
> Optimize for sequencial write. Layout infos and tags are organized by
> file offset. When appending data to a file whole list will be examined,
> which introduce notable performance decrease.
Looks good to me.
Fred, can you please double check?
Benny
P.S.: Zhang, please note Fred's new email address
>
> Signed-off-by: Zhang Jingwang <zhangjingwang@xxxxxxxxxxxx>
> ---
> fs/nfs/blocklayout/extents.c | 126 +++++++++++++++++++++---------------------
> 1 files changed, 64 insertions(+), 62 deletions(-)
>
> diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
> index 3c311f2..514f2cc 100644
> --- a/fs/nfs/blocklayout/extents.c
> +++ b/fs/nfs/blocklayout/extents.c
> @@ -66,8 +66,8 @@ static int32_t _find_entry(struct my_tree_t *tree, u64 s)
> struct pnfs_inval_tracking *pos;
>
> dprintk("%s(%llu) enter\n", __func__, s);
> - list_for_each_entry(pos, &tree->mtt_stub, it_link) {
> - if (pos->it_sector < s)
> + list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
> + if (pos->it_sector > s)
> continue;
> else if (pos->it_sector == s)
> return pos->it_tags & INTERNAL_MASK;
> @@ -102,8 +102,8 @@ static int _add_entry(struct my_tree_t *tree, u64 s, int32_t tag,
> struct pnfs_inval_tracking *pos;
>
> dprintk("%s(%llu, %i, %p) enter\n", __func__, s, tag, storage);
> - list_for_each_entry(pos, &tree->mtt_stub, it_link) {
> - if (pos->it_sector < s)
> + list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
> + if (pos->it_sector > s)
> continue;
> else if (pos->it_sector == s) {
> found = 1;
> @@ -125,7 +125,7 @@ static int _add_entry(struct my_tree_t *tree, u64 s, int32_t tag,
> }
> new->it_sector = s;
> new->it_tags = (1 << tag);
> - list_add_tail(&new->it_link, &pos->it_link);
> + list_add(&new->it_link, &pos->it_link);
> return 1;
> }
> }
> @@ -230,14 +230,14 @@ _range_has_tag(struct my_tree_t *tree, u64 start, u64 end, int32_t tag)
> u64 expect = 0;
>
> dprintk("%s(%llu, %llu, %i) enter\n", __func__, start, end, tag);
> - list_for_each_entry(pos, &tree->mtt_stub, it_link) {
> - if (pos->it_sector < start)
> + list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
> + if (pos->it_sector >= end)
> continue;
> if (!expect) {
> - if ((pos->it_sector == start) &&
> + if ((pos->it_sector == end - tree->mtt_step_size) &&
> (pos->it_tags & (1 << tag))) {
> - expect = start + tree->mtt_step_size;
> - if (expect == end)
> + expect = pos->it_sector - tree->mtt_step_size;
> + if (expect < start)
> return 1;
> continue;
> } else {
> @@ -246,8 +246,8 @@ _range_has_tag(struct my_tree_t *tree, u64 start, u64 end, int32_t tag)
> }
> if (pos->it_sector != expect || !(pos->it_tags & (1 << tag)))
> return 0;
> - expect += tree->mtt_step_size;
> - if (expect == end)
> + expect -= tree->mtt_step_size;
> + if (expect < start)
> return 1;
> }
> return 0;
> @@ -594,65 +594,67 @@ add_and_merge_extent(struct pnfs_block_layout *bl,
> /* Scan for proper place to insert, extending new to the left
> * as much as possible.
> */
> - list_for_each_entry_safe(be, tmp, list, be_node) {
> - if (new->be_f_offset < be->be_f_offset)
> + list_for_each_entry_safe_reverse(be, tmp, list, be_node) {
> + if (new->be_f_offset >= be->be_f_offset + be->be_length)
> break;
> - if (end <= be->be_f_offset + be->be_length) {
> - /* new is a subset of existing be*/
> + if (new->be_f_offset >= be->be_f_offset) {
> + if (end <= be->be_f_offset + be->be_length) {
> + /* new is a subset of existing be*/
> + if (extents_consistent(be, new)) {
> + dprintk("%s: new is subset, ignoring\n",
> + __func__);
> + put_extent(new);
> + return 0;
> + } else {
> + goto out_err;
> + }
> + } else {
> + /* |<-- be -->|
> + * |<-- new -->| */
> + if (extents_consistent(be, new)) {
> + /* extend new to fully replace be */
> + new->be_length += new->be_f_offset -
> + be->be_f_offset;
> + new->be_f_offset = be->be_f_offset;
> + new->be_v_offset = be->be_v_offset;
> + dprintk("%s: removing %p\n", __func__, be);
> + list_del(&be->be_node);
> + put_extent(be);
> + } else {
> + goto out_err;
> + }
> + }
> + } else if (end >= be->be_f_offset + be->be_length) {
> + /* new extent overlap existing be */
> if (extents_consistent(be, new)) {
> - dprintk("%s: new is subset, ignoring\n",
> - __func__);
> - put_extent(new);
> - return 0;
> - } else
> + /* extend new to fully replace be */
> + dprintk("%s: removing %p\n", __func__, be);
> + list_del(&be->be_node);
> + put_extent(be);
> + } else {
> goto out_err;
> - } else if (new->be_f_offset <=
> - be->be_f_offset + be->be_length) {
> - /* new overlaps or abuts existing be */
> - if (extents_consistent(be, new)) {
> + }
> + } else if (end > be->be_f_offset) {
> + /* |<-- be -->|
> + *|<-- new -->| */
> + if (extents_consistent(new, be)) {
> /* extend new to fully replace be */
> - new->be_length += new->be_f_offset -
> - be->be_f_offset;
> - new->be_f_offset = be->be_f_offset;
> - new->be_v_offset = be->be_v_offset;
> + new->be_length += be->be_f_offset + be->be_length -
> + new->be_f_offset - new->be_length;
> dprintk("%s: removing %p\n", __func__, be);
> list_del(&be->be_node);
> put_extent(be);
> - } else if (new->be_f_offset !=
> - be->be_f_offset + be->be_length)
> + } else {
> goto out_err;
> + }
> }
> }
> /* Note that if we never hit the above break, be will not point to a
> * valid extent. However, in that case &be->be_node==list.
> */
> - list_add_tail(&new->be_node, &be->be_node);
> + list_add(&new->be_node, &be->be_node);
> dprintk("%s: inserting new\n", __func__);
> print_elist(list);
> - /* Scan forward for overlaps. If we find any, extend new and
> - * remove the overlapped extent.
> - */
> - be = list_prepare_entry(new, list, be_node);
> - list_for_each_entry_safe_continue(be, tmp, list, be_node) {
> - if (end < be->be_f_offset)
> - break;
> - /* new overlaps or abuts existing be */
> - if (extents_consistent(be, new)) {
> - if (end < be->be_f_offset + be->be_length) {
> - /* extend new to fully cover be */
> - end = be->be_f_offset + be->be_length;
> - new->be_length = end - new->be_f_offset;
> - }
> - dprintk("%s: removing %p\n", __func__, be);
> - list_del(&be->be_node);
> - put_extent(be);
> - } else if (end != be->be_f_offset) {
> - list_del(&new->be_node);
> - goto out_err;
> - }
> - }
> - dprintk("%s: after merging\n", __func__);
> - print_elist(list);
> /* STUB - The per-list consistency checks have all been done,
> * should now check cross-list consistency.
> */
> @@ -685,10 +687,10 @@ find_get_extent(struct pnfs_block_layout *bl, sector_t isect,
> if (ret &&
> (!cow_read || ret->be_state != PNFS_BLOCK_INVALID_DATA))
> break;
> - list_for_each_entry(be, &bl->bl_extents[i], be_node) {
> - if (isect < be->be_f_offset)
> + list_for_each_entry_reverse(be, &bl->bl_extents[i], be_node) {
> + if (isect >= be->be_f_offset + be->be_length)
> break;
> - if (isect < be->be_f_offset + be->be_length) {
> + if (isect >= be->be_f_offset) {
> /* We have found an extent */
> dprintk("%s Get %p (%i)\n", __func__, be,
> atomic_read(&be->be_refcnt.refcount));
> @@ -721,10 +723,10 @@ find_get_extent_locked(struct pnfs_block_layout *bl, sector_t isect)
> for (i = 0; i < EXTENT_LISTS; i++) {
> if (ret)
> break;
> - list_for_each_entry(be, &bl->bl_extents[i], be_node) {
> - if (isect < be->be_f_offset)
> + list_for_each_entry_reverse(be, &bl->bl_extents[i], be_node) {
> + if (isect >= be->be_f_offset + be->be_length)
> break;
> - if (isect < be->be_f_offset + be->be_length) {
> + if (isect >= be->be_f_offset) {
> /* We have found an extent */
> dprintk("%s Get %p (%i)\n", __func__, be,
> atomic_read(&be->be_refcnt.refcount));
--
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