On Tue, Jan 16, 2007 at 01:53:25PM -0800, Andrew Morton wrote: > > On Mon, 15 Jan 2007 21:47:43 -0800 (PST) Christoph Lameter > > <[EMAIL PROTECTED]> wrote: > > > > Currently cpusets are not able to do proper writeback since dirty ratio > > calculations and writeback are all done for the system as a whole. > > We _do_ do proper writeback. But it's less efficient than it might be, and > there's an NFS problem. > > > This may result in a large percentage of a cpuset to become dirty without > > writeout being triggered. Under NFS this can lead to OOM conditions. > > OK, a big question: is this patchset a performance improvement or a > correctness fix? Given the above, and the lack of benchmark results I'm > assuming it's for correctness.
Given that we've already got a 25-30% buffered write performance degradation between 2.6.18 and 2.6.20-rc4 for simple sequential write I/O to multiple filesystems concurrently, I'd really like to see some serious I/O performance regression testing on this change before it goes anywhere. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
