On Mon, Jun 30, 2014 at 03:09:14PM -0700, Andrew Morton wrote: > On Mon, 30 Jun 2014 22:51:21 +0100 Mel Gorman <mgorman@xxxxxxx> wrote: > > > > That's a large change in system time. Does this all include kswapd > > > activity? > > > > > > > I don't have a profile to quantify that exactly. It takes 7 hours to > > complete a test on that machine in this configuration > > That's nuts. Why should measuring this require more than a few minutes? That's how long the full test takes to complete for each part of the IO test. Profiling a subsection of it will miss some parts with no guarantee the sampled subset is representative. Profiling for smaller amounts of IO so the test completes quickly does not guarantee that the sample is representative. Reducing the size of memory of the machine using any tricks is also not representative etc. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>