Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19

Adam Litke
2005-11-07T16:43:40Z

On Fri, 2005-11-04 at 08:44 +0100, Eric Dumazet wrote:
> Paul Jackson a ecrit :
> > Linus wrote:
> >
> >>Maybe you'd be willing on compromising by using a few kernel boot-time
> >>command line options for your not-very-common load.
> >
> >
> > If we were only a few options away from running Andy's varying load
> > mix with something close to ideal performance, we'd be in fat city,
> > and Andy would never have been driven to write that rant.
>
> I found hugetlb support in linux not very practical/usable on NUMA machines,
> boot-time parameters or /proc/sys/vm/nr_hugepages.
>
> With this single integer parameter, you cannot allocate 1000 4MB pages on one
> specific node, letting small pages on another node.
>
> I'm not an astrophysician, nor a DB admin, I'm only trying to partition a dual
> node machine between one (numa aware) memory intensive job and all others
> (system, network, shells).
> At least I can reboot it if needed, but I feel Andy pain.
>
> There is a /proc/buddyinfo file, maybe we need a /proc/sys/vm/node_hugepages
> with a list of integers (one per node) ?

Or perhaps /sys/devices/system/node/nodeX/nr_hugepages triggers that
work like the current /proc trigger but on a per node basis?

--
Adam Litke - (agl at us.ibm.com)
IBM Linux Technology Center