On Fri, 2018-06-15 at 18:55 +0200, Hannes Reinecke wrote: > 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'. That's a cumbersome approach, illustrated by the fact that Mel forgot to use direct writes in his examples. If Mel overlooked that more people will overlook to use direct writes. Bart.
