2013-05-06 11:25:14

by Haicheng Li

Subject: [PATCH] f2fs: optimize alloc_nid_failed()

Current alloc_nid_failed() has two issues:
1. unecessarily kmem_cache_free() the free_nid and then realloc a new
slab cache for it immediately;
2. needs to __lookup_free_nid_list() twice in order to find out the free_nid
from free_nid_list.

This patch fixes these issues.

Signed-off-by: Haicheng Li <[email protected]>
---
fs/f2fs/node.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index e275218..7ce8e9f 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1403,8 +1403,21 @@ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
*/
void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
{
- alloc_nid_done(sbi, nid);
- add_free_nid(NM_I(sbi), nid);
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ struct free_nid *i;
+
+ spin_lock(&nm_i->free_nid_list_lock);
+ i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+ if (i) {
+ BUG_ON(i->state != NID_ALLOC);
+ if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
+ __del_from_free_nid_list(i);
+ else {
+ i->state = NID_NEW;
+ nm_i->fcnt++;
+ }
+ }
+ spin_unlock(&nm_i->free_nid_list_lock);
}

void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
--
1.7.9.5

2013-05-06 13:20:16

by Haicheng Li

Subject: Re: [PATCH] f2fs: optimize alloc_nid_failed()

Just realized I should develop the patches against Kim's f2fs-dev branch
rather than the f2fs-master branch. (thanks to Huajun for the reminding).

Obviously on f2fs-dev branch, some optimizations of alloc_nid_failed() have
already been done.

Pls. ignore this patch, I'll send out the rebased version of my recent f2fs
patches soon later, which will be based on the f2fs-dev tree.

On Mon, May 06, 2013 at 07:25:06PM +0800, Haicheng Li wrote:
> Current alloc_nid_failed() has two issues:
> 1. unecessarily kmem_cache_free() the free_nid and then realloc a new
> slab cache for it immediately;
> 2. needs to __lookup_free_nid_list() twice in order to find out the free_nid
> from free_nid_list.
>
> This patch fixes these issues.
>
> Signed-off-by: Haicheng Li <[email protected]>
> ---
> fs/f2fs/node.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index e275218..7ce8e9f 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1403,8 +1403,21 @@ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
> */
> void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
> {
> - alloc_nid_done(sbi, nid);
> - add_free_nid(NM_I(sbi), nid);
> + struct f2fs_nm_info *nm_i = NM_I(sbi);
> + struct free_nid *i;
> +
> + spin_lock(&nm_i->free_nid_list_lock);
> + i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
> + if (i) {
> + BUG_ON(i->state != NID_ALLOC);
> + if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
> + __del_from_free_nid_list(i);
> + else {
> + i->state = NID_NEW;
> + nm_i->fcnt++;
> + }
> + }
> + spin_unlock(&nm_i->free_nid_list_lock);
> }
>
> void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
> --
> 1.7.9.5