[PATCH v6 00/17] mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8

[Tomonori Fujita]

Hi,

On Thu, 8 Jun 2023 14:29:45 -0700
Isaac Manjarres <isaacmanjarres at google.com> wrote:

> P.S. I noticed that the trace_swiotlb_bounced() tracepoint may not be  
>invoked even though bouncing occurs. For example, in the dma-iommu 
>path,
> swiotlb_tbl_map_single() is called when bouncing, instead of  
>swiotlb_map(), which is what ends up calling trace_swiotlb_bounced().
> 
> Would it make sense to move the call to trace_swiotlb_bounced() to
> swiotlb_tbl_map_single() since that function is always invoked?

Definitely, if you ask me. I believe the change was merely forgotten in commit eb605a5754d0 ("swiotlb: add swiotlb_tbl_map_single library function").

Let me take the author into Cc. Plus Konrad, who built further on that commit, may also have an opinion.

When I wrote the patch, trace_swiotlb_bounced() existed?

I cannot recall the patch but from quick look, moving trace_swiotlb_bounced() to
swiotlb_tbl_map_single() makes sense.

thanks