On 4/19/21 2:16 PM, Michal Hocko wrote: > 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? I fix doc in next version. Im not sure what you expect the commit message to include. The function of the meminfo is: (From Documentation/filesystems/proc.rst) "Provides information about distribution and utilization of memory." Im not the designed of dma-buf, I think global_node_page_state as a kernel internal. dma-buf is a device driver that provides a function so I might be on the outside. However I also see that it might be relevant for a OOM. It is memory that can be freed by killing userspace processes. The show_mem thing. Should it be a separate patch?
