Re: [PATCH] btrfs: Simplify the allocation of slab caches in btrfs_delayed_inode_init

[Kunwu Chan]

On 2024/1/31 18:20, Johannes Thumshirn wrote:
> On 31.01.24 07:20, Kunwu Chan wrote:
> > commit 0a31bd5f2bbb ("KMEM_CACHE(): simplify slab cache creation")
> > introduces a new macro.
> > Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
>
> That commit is 17 years old. Why should we switch to it _now_? I
> wouldn't call it a new macro.
>
> Don't get me wrong, I don't oppose the patch, but I'd prefer a better
> explanation why now and not 17 years ago when the macro got introduced.
Thanks for your attention.
Like David say in 
https://lore.kernel.org/all/20240131183929.GP31555@xxxxxxxxxxxxx/#t.

The main reason is 'it hides all the 0 or NULL parameters', makes the 
code cleaner and more readable.

So i'll update the commit msg to this:

Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Make the code cleaner and more readable.

And resend a v2 patch.
Thanks again.
> > to simplify the creation of SLAB caches.
> >
> > Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
> > ---
> >    fs/btrfs/delayed-inode.c | 6 +-----
> >    1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
> > index 08102883f560..8c748c6cdf6d 100644
> > --- a/fs/btrfs/delayed-inode.c
> > +++ b/fs/btrfs/delayed-inode.c
> > @@ -28,11 +28,7 @@ static struct kmem_cache *delayed_node_cache;
> >    
> >    int __init btrfs_delayed_inode_init(void)
> >    {
> > -	delayed_node_cache = kmem_cache_create("btrfs_delayed_node",
> > -					sizeof(struct btrfs_delayed_node),
> > -					0,
> > -					SLAB_MEM_SPREAD,
> > -					NULL);
> > +	delayed_node_cache = KMEM_CACHE(btrfs_delayed_node, SLAB_MEM_SPREAD);
> >    	if (!delayed_node_cache)
> >    		return -ENOMEM;
> >    	return 0;
--
Thanks,
  Kunwu