On 06/15/2018 04:07 PM, Bart Van Assche wrote:
On Thu, 2018-06-14 at 15:38 +0200, Hannes Reinecke wrote:
For performance reasons we should be able to allocate all memory
from a given NUMA node, so this patch adds a new parameter
'rd_numa_node' to allow the user to specify the NUMA node id.
When restricing fio to use the same NUMA node I'm seeing a performance
boost of more than 200%.
Passing this information through a kernel module parameter to the brd kernel
module seems wrong to me. There can be multiple brd instances. Using a kernel
module parameter makes it impossible to specify a different NUMA node for
different brd instances.
This patch has primarily done for simplicity; all the existing brd
parameters affect _all_ ramdisks, so this patch keeps that style.
If you want soemthing more fine-grained you could use the approach
suggested by Mel Gorman and use 'numactl' to pre-fill the ramdisk via 'dd'.
Cheers,
Hannes
