On Mon, Feb 20, 2006 at 07:58:35PM +0000, Joern RENNECKE wrote: > H. J. Lu wrote: > > >On Mon, Feb 20, 2006 at 07:30:41PM +0000, Joern RENNECKE wrote: > > > > > >>the bottleneck of a shared memory bus, but the operating system must > >>allocate > >>most memory locally to each CPU to avoid a bottleneck in the > >>cross-connect > >>of the processors. > >> > >> > >> > > > >Linux kernel 2.6.16-rc1 and above supports > > > >percpu_pagelist_fraction > > > > > Is this per cpu (which might contain multiple cores) or per core?
I think it is per core. But I don't know if a HT cpu counts here or not. > > >This is the fraction of pages at most (high mark pcp->high) in each zone > >that > >are allocated for each per cpu page list. The min value for this is 8. > >It > >means that we don't allow more than 1/8th of pages in each zone to be > >allocated in any single per_cpu_pagelist. > > > Do I understand this correctly that in a dual opteron single core system > with 2 GB > memory, only up to 256 MB per processor could be specifically allocated > in local > memory? > Whereas in an 8-way opteron machine with equal amounts of memory > attached to each > processor, all the local memory could be allocated to its processor? I don't know the answer. You may ask it on the Linux kernel mailing list. H.J.
