On Fri, Mar 06, 2015 at 11:34:29AM +0100, Imre Palik wrote: > On 02/26/15 17:34, David Miller wrote: > > From: Imre Palik <imrep@xxxxxxxxx> > > Date: Thu, 26 Feb 2015 11:19:25 +0100 > > > >> If you are looking for peculiarities in my setup then here they are: > >> I am on 4k pages, and perf is not working :-( > >> (I am trying to fix those too, but that is far from being a low hanging fruit.) > >> So my guess would be that the packet pipeline doesn't fit in the cache/tlb > > > > Pure specualtion until you can actually use perf to measure these > > things. > > > > And I don't want to apply patches which were designed based upon > > pure speculation. > > > > I did performance measurements in the following way: > > Removed those pieces of the packet pipeline that I don't necessarily > need one-by-one. Then measured their effect on small packet > performance. > > This was the only part that produced considerable effect. > > The pure speculation was about why the effect is more than 15% > increase in packet throughput, although the code path avoided > contains way less code than 15% of the packet pipeline. It seems, > Felix Fietkau profiled similar changes, and found my guess well > founded. > > Now could anybody explain me what else is wrong with my patch? We have to come up with a more generic solution for this. These sysfs tweaks you're proposing look to me like an obscure way to tune this.
