9 Oct
2026
9 Oct
'26
12:42 p.m.
On Mon, Oct 05, 2026 at 08:41:32AM +0200, Karl Mehltretter wrote:
static inline struct page *sg_page(struct scatterlist *sg) { #ifdef CONFIG_DEBUG_SG BUG_ON(sg_is_chain(sg)); #endif
- sg_dmabuf_cpu_access_check(sg); return (struct page *)((sg)->page_link & ~SG_PAGE_LINK_MASK);
}
I'm not sure I understand the overall intention here, I get what this patch does, but no distro could turn this on by default when it touches *everyone* using scatterlist in a performance sensitive spot, and anyone doing testing can use the existing option - so what is the point?
I certainly don't like this patch, and I don't like the word "DMABUF" in the scatterlist at all. If we want to add something it should be a general mechanism under DEBUG_SG that allows anyone to 'hide' the CPU list from any future access.
Jason