Re: [PATCH v4] dma-buf: Add DmaBufTotal counter in meminfo

[Michal Hocko]

On Sat 17-04-21 12:40:32, Peter Enderborg wrote:
> This adds a total used dma-buf memory. Details
> can be found in debugfs, however it is not for everyone
> and not always available. dma-buf are indirect allocated by
> userspace. So with this value we can monitor and detect
> userspace applications that have problems.

The changelog would benefit from more background on why this is needed,
and who is the primary consumer of that value.

I cannot really comment on the dma-buf internals but I have two remarks.
Documentation/filesystems/proc.rst needs an update with the counter
explanation and secondly is this information useful for OOM situations
analysis? If yes then show_mem should dump the value as well.

>From the implementation point of view, is there any reason why this
hasn't used the existing global_node_page_state infrastructure?
-- 
Michal Hocko
SUSE Labs