> > On Wed, Aug 23, 2017 at 8:58 AM, Tim Chen > wrote: > > > > Will you still consider the original patch as a fail safe mechanism? > > I don't think we have much choice, although I would *really* want to get this > root-caused rather than just papering over the symptoms. > > Maybe still worth testing that "sched/numa: Scale scan period with tasks in > group and shared/private" patch that Mel mentioned. The patch doesn’t help on our load. Thanks, Kan > > In fact, looking at that patch description, it does seem to match this particular > load a lot. Quoting from the commit message: > > "Running 80 tasks in the same group, or as threads of the same process, > results in the memory getting scanned 80x as fast as it would be if a > single task was using the memory. > > This really hurts some workloads" > > So if 80 threads causes 80x as much scanning, a few thousand threads might > indeed be really really bad. > > So once more unto the breach, dear friends, once more. > > Please. > > The patch got applied to -tip as commit b5dd77c8bdad, and can be > downloaded here: > > > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=b5dd > 77c8bdada7b6262d0cba02a6ed525bf4e6e1 > > (Hmm. It says it's cc'd to me, but I never noticed that patch simply because it > was in a big group of other -tip commits.. Oh well). > > Linus N‹§²æìr¸›zǧu©ž²Æ {­†éì¹»®&Þ–)îÆi¢žØ^n‡r¶‰šŽŠÝ¢j$½§$¢¸¢¹¨­è§~Š'.)îÄÃ,yèm¶Ÿÿà %Š{±šj+ƒðèž×¦j)Z†·Ÿ