Re: [PATCH] ipc/msg: allocate msg_msgseg from kmem buckets

[Jan Kara]

On Tue 30-06-26 14:17:12, Yi Xie wrote:
> struct msg_msg already comes from dedicated kmem buckets, but the
> follow-on msg_msgseg chunks for larger payloads still use kmalloc.
> 
> Switch the segment allocations to kmem buckets as well.  Still free them
> with kfree(), same as msg_msg.
> 
> Signed-off-by: Yi Xie <xieyi@xxxxxxxxxx>

Although I can see why get_maintainer script picked me and Christian I
don't think we are the right people to review this patch :). Let me CC Kees
who added the buckets usage to msg. Kees?

								Honza

> ---
>  ipc/msgutil.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/ipc/msgutil.c b/ipc/msgutil.c
> index e28f0cecb2ec..8aa8ac180317 100644
> --- a/ipc/msgutil.c
> +++ b/ipc/msgutil.c
> @@ -40,6 +40,7 @@ struct msg_msgseg {
>  #define DATALEN_SEG	((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
>  
>  static kmem_buckets *msg_buckets __ro_after_init;
> +static kmem_buckets *msgseg_buckets __ro_after_init;
>  
>  static int __init init_msg_buckets(void)
>  {
> @@ -47,6 +48,10 @@ static int __init init_msg_buckets(void)
>  					  sizeof(struct msg_msg),
>  					  DATALEN_MSG, NULL);
>  
> +	msgseg_buckets = kmem_buckets_create("msg_msgseg", SLAB_ACCOUNT,
> +					     sizeof(struct msg_msgseg),
> +					     DATALEN_SEG, NULL);
> +
>  	return 0;
>  }
>  subsys_initcall(init_msg_buckets);
> @@ -73,7 +78,8 @@ static struct msg_msg *alloc_msg(size_t len)
>  		cond_resched();
>  
>  		alen = min(len, DATALEN_SEG);
> -		seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT);
> +		seg = kmem_buckets_alloc(msgseg_buckets,
> +					 sizeof(*seg) + alen, GFP_KERNEL);
>  		if (seg == NULL)
>  			goto out_err;
>  		*pseg = seg;
> -- 
> 2.25.1
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR