On 2017/8/25 3:03, Jaegeuk Kim wrote:
> This patch fixes to avoid needless wake ups.
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/f2fs/segment.c | 3 +--
> fs/f2fs/segment.h | 25 +++++++++++++++++++++++++
> fs/f2fs/sysfs.c | 6 +-----
> 3 files changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 8306beace7cb..8375257b6b26 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1494,8 +1494,7 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
> kmem_cache_free(discard_entry_slab, entry);
> }
>
> - dcc->discard_wake = 1;
> - wake_up_interruptible_all(&dcc->discard_wait_queue);
> + wake_up_discard_thread(sbi, false);
> }
>
> static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> index b9b4f85ffeb6..5099e12ee808 100644
> --- a/fs/f2fs/segment.h
> +++ b/fs/f2fs/segment.h
> @@ -798,3 +798,28 @@ static inline long nr_pages_to_write(struct f2fs_sb_info *sbi, int type,
> wbc->nr_to_write = desired;
> return desired - nr_to_write;
> }
> +
> +static inline void wake_up_discard_thread(struct f2fs_sb_info *sbi, bool force)
> +{
> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> + bool wakeup = false> + int i;
> +
> + if (force)
> + goto wake_up;
> +
> + mutex_lock(&dcc->cmd_lock);
> + for (i = MAX_PLIST_NUM - 1;
> + i >= 0 && plist_issue(dcc->pend_list_tag[i]); i--) {
> + if (!list_empty(&dcc->pend_list[i])) {
> + wakeup = true;
> + break;
> + }
> + }
> + mutex_unlock(&dcc->cmd_lock);
> + if (wakeup)
if (!wakeup)
Other part looks good to me,
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Thanks,
> + return;
> +wake_up:
> + dcc->discard_wake = 1;
> + wake_up_interruptible_all(&dcc->discard_wait_queue);
> +}
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index b9ad9041559f..962735dc9c63 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -178,13 +178,9 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
> if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0)
> f2fs_reset_iostat(sbi);
> if (!strcmp(a->attr.name, "gc_urgent") && t == 1 && sbi->gc_thread) {
> - struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> -
> sbi->gc_thread->gc_wake = 1;
> wake_up_interruptible_all(&sbi->gc_thread->gc_wait_queue_head);
> -
> - dcc->discard_wake = 1;
> - wake_up_interruptible_all(&dcc->discard_wait_queue);
> + wake_up_discard_thread(sbi, true);
> }
>
> return count;
>
