Re: [PATCH 4/5] debugobjects: Use hlist_splice_init() to reduce lock conflicts
From: Thomas Gleixner
Date: Tue Sep 03 2024 - 06:10:14 EST
On Mon, Sep 02 2024 at 22:05, Zhen Lei wrote:
> The sub list can be prepared in advance outside the lock, so that the
> operation time inside the lock can be reduced and the possibility of
> lock conflict can be reduced.
>
> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
> ---
> lib/debugobjects.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/lib/debugobjects.c b/lib/debugobjects.c
> index fc8224f9f0eda8f..998724e9dee526b 100644
> --- a/lib/debugobjects.c
> +++ b/lib/debugobjects.c
> @@ -167,23 +167,25 @@ static void fill_pool(void)
> return;
>
> while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
> - struct debug_obj *new[ODEBUG_BATCH_SIZE];
> + HLIST_HEAD(batch_list);
> + struct debug_obj *new, *last;
Variable ordering please.
> int cnt;
>
> for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) {
> - new[cnt] = kmem_cache_zalloc(obj_cache, gfp);
> - if (!new[cnt])
> + new = kmem_cache_zalloc(obj_cache, gfp);
> + if (!new)
> break;
> + hlist_add_head(&new->node, &batch_list);
> + if (cnt == 0)
if (!cnt)
but it would be more self explaining if you have:
struct debug_obj *new, *last = NULL;
and then
if (!last)
> + last = new;
> }
Thanks,
tglx