On Wed, 2013-01-23 at 16:30 +0800, Michael Wang wrote: > On 01/23/2013 04:20 PM, Mike Galbraith wrote: > > On Wed, 2013-01-23 at 15:10 +0800, Michael Wang wrote: > >> On 01/23/2013 02:28 PM, Mike Galbraith wrote: > > > >>> Abbreviated test run: > >>> Tasks jobs/min jti jobs/min/task real cpu > >>> 640 158044.01 81 246.9438 24.54 577.66 Wed Jan 23 > >>> 07:14:33 2013 > >>> 1280 50434.33 39 39.4018 153.80 5737.57 Wed Jan 23 > >>> 07:17:07 2013 > >>> 2560 47214.07 34 18.4430 328.58 12715.56 Wed Jan 23 > >>> 07:22:36 2013 > >> > >> So still not works... and not going to balance path while waking up will > >> fix it, looks like that's the only choice if no error on balance path > >> could be found...benchmark wins again, I'm feeling bad... > >> > >> I will conclude the info we collected and make a v3 later. > > > > FWIW, I hacked virgin to do full balance if an idle CPU was not found, > > leaving the preference to wake cache affine intact though, turned on > > WAKE_BALANCE in all domains, and it did not collapse. In fact, the high > > load end, where the idle search will frequently be a waste of cycles, > > actually improved a bit. Things that make ya go hmmm. > > Oh, does that means the old balance path is good while the new is really > broken, I mean, compared this with the previously results, could we say > that all the collapse was just caused by the change of balance path?
That's a good supposition. I'll see if it holds. Next, I'm going to try ripping select_idle_sibling() to tiny shreds, twiddle the balance path a little to see if I can get rid of the bad stuff for tbench, maybe make some good stuff for pgbench and ilk, ilk _maybe_ including heavy duty remote network type loads. There's gonna be some violent axe swinging here shortly. -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/
