On Mon, 2013-01-21 at 10:44 +0100, Mike Galbraith wrote: > On Mon, 2013-01-21 at 17:22 +0800, Michael Wang wrote: > > On 01/21/2013 05:09 PM, Mike Galbraith wrote: > > > On Mon, 2013-01-21 at 15:45 +0800, Michael Wang wrote: > > >> On 01/21/2013 03:09 PM, Mike Galbraith wrote: > > >>> On Mon, 2013-01-21 at 07:42 +0100, Mike Galbraith wrote: > > >>>> On Mon, 2013-01-21 at 13:07 +0800, Michael Wang wrote: > > >>> > > >>>>> May be we could try change this back to the old way later, after the > > >>>>> aim > > >>>>> 7 test on my server. > > >>>> > > >>>> Yeah, something funny is going on. > > >>> > > >>> Never entering balance path kills the collapse. Asking wake_affine() > > >>> wrt the pull as before, but allowing us to continue should no idle cpu > > >>> be found, still collapsed. So the source of funny behavior is indeed in > > >>> balance_path. > > >> > > >> Below patch based on the patch set could help to avoid enter balance path > > >> if affine_sd could be found, just like the old logical, would you like to > > >> take a try and see whether it could help fix the collapse? > > > > > > No, it does not. > > > > Hmm...what have changed now compared to the old logical? > > What I did earlier to confirm the collapse originates in balance_path is > below. I just retested to confirm.
... And you can add.. if (per_cpu(sd_llc_id, cpu) == per_cpu(sd_llc_id, prev_cpu)) goto unlock; ..before calling select_idle_sibling() the second time to optimize department of redundancy department idle search algorithm ;-) -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
