On 5/31/23 17:48, Catalin Marinas wrote:
> If an architecture opted in to DMA bouncing of unaligned kmalloc()
> buffers (ARCH_WANT_KMALLOC_DMA_BOUNCE), reduce the minimum kmalloc()
> cache alignment below cache-line size to ARCH_KMALLOC_MINALIGN.
>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Nit below:
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> ---
> mm/slab_common.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 7c6475847fdf..fe46459a8b77 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -18,6 +18,7 @@
> #include <linux/uaccess.h>
> #include <linux/seq_file.h>
> #include <linux/dma-mapping.h>
> +#include <linux/swiotlb.h>
> #include <linux/proc_fs.h>
> #include <linux/debugfs.h>
> #include <linux/kasan.h>
> @@ -863,10 +864,19 @@ void __init setup_kmalloc_cache_index_table(void)
> }
> }
>
> +#ifdef CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC
> +static unsigned int __kmalloc_minalign(void)
> +{
> + if (io_tlb_default_mem.nslabs)
> + return ARCH_KMALLOC_MINALIGN;
> + return dma_get_cache_alignment();
> +}
> +#else
> static unsigned int __kmalloc_minalign(void)
> {
> return dma_get_cache_alignment();
> }
> +#endif
Should be enough to put the #ifdef around the two lines into a single
implementation of the function?
> void __init
> new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
>
