On Wed, May 20, 2015 at 12:24:21PM -0400, Johannes Weiner wrote: > > > > Low thread counts get a small boost but it's within noise as memcg overhead > > does not dominate. It's not obvious at all at higher thread counts as other > > factors cause more problems. The overall breakdown of CPU usage looks like > > > > 4.0.0 4.0.0 > > chargefirst-v2r1disable-v2r1 > > User 41.81 41.45 > > System 407.64 405.50 > > Elapsed 128.17 127.06 > > This is a worst case microbenchmark doing nothing but anonymous page > faults (with THP disabled), and yet the performance difference is in > the noise. I don't see why we should burden the user with making a > decision that doesn't matter in theory, let alone in practice. > > We have CONFIG_MEMCG and cgroup_disable=memory, that should be plenty > for users that obsess about fluctuation in the noise. There is no > reason to complicate the world further for everybody else. FWIW, I agree and only included this patch because I said I would yesterday. After patch 1, there is almost no motivation to disable memcg at all let alone by default. -- 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>