Re: linux-next: manual merge of the bcachefs tree with the mm-unstable tree

[Andrew Morton]

On Tue, 19 Aug 2025 11:12:28 +1000 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:

> Hi all,
> 
> Today's linux-next merge of the bcachefs tree got a conflict in:
> 
>   fs/bcachefs/darray.c
> 
> between commit:
> 
>   97b75b7e275a ("mm/slub: allow to set node and align in k[v]realloc")
> 
> from the mm-unstable tree and commit:
> 
>   808708fe9da0 ("bcachefs: darray_make_room_rcu()")
> 
> from the bcachefs tree.
> 
> ...
>
> --- a/fs/bcachefs/darray.c
> +++ b/fs/bcachefs/darray.c
> @@@ -20,10 -22,11 +22,11 @@@ int __bch2_darray_resize_noprof(darray_
>   		if (unlikely(check_mul_overflow(new_size, element_size, &bytes)))
>   			return -ENOMEM;
>   
> - 		void *data = likely(bytes < INT_MAX)
> + 		void *old = d->data;
> + 		void *new = likely(bytes < INT_MAX)
>  -			? kvmalloc_noprof(bytes, gfp)
>  +			? kvmalloc_node_align_noprof(bytes, 1, gfp, NUMA_NO_NODE)
>   			: vmalloc_noprof(bytes);
> - 		if (!data)
> + 		if (!new)
>   			return -ENOMEM;

uh, OK, I guess a 2GB allocation is reasonable on a 16TB machine.

But why does bcachefs find it necessary to bypass allocation profiling?