determining bus_dma memory usage by driver

Chuck Tuffli ctuffli at
Tue Oct 25 16:27:26 UTC 2011

On Mon, Oct 24, 2011 at 8:38 PM, Matthew Jacob <mj at> wrote:
> On 10/24/2011 5:21 PM, Chuck Tuffli wrote:
>> Is there an easy way to determine the amount of bus_dma memory
>> allocated by a driver? Something similar to vmstat -m
> bus_dma memory allocations are platform specific. Looking at least amd64 you can see that the memory is carved out M_DEVBUF.

OK, so do a diff of

vmstat -m | grep devbuf

before and after driver load would get me the right number? Does this
double count any memory reported by the MALLOC_DEFINE()?


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