Hey Miklos On Fri, 18 Jun 2021 at 16:42, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > On Fri, 18 Jun 2021 at 10:31, Michael Stapelberg > <stapelberg+linux@xxxxxxxxxx> wrote: > > > Maybe, but I don’t have the expertise, motivation or time to > > investigate this any further, let alone commit to get it done. > > During our previous discussion I got the impression that nobody else > > had any cycles for this either: > > https://lore.kernel.org/linux-fsdevel/CANnVG6n=ySfe1gOr=0ituQidp56idGARDKHzP0hv=ERedeMrMA@xxxxxxxxxxxxxx/ > > > > Have you had a look at the China LSF report at > > http://bardofschool.blogspot.com/2011/? > > The author of the heuristic has spent significant effort and time > > coming up with what we currently have in the kernel: > > > > """ > > Fengguang said he draw more than 10K performance graphs and read even > > more in the past year. > > """ > > > > This implies that making changes to the heuristic will not be a quick fix. > > Having a piece of kernel code sitting there that nobody is willing to > fix is certainly not a great situation to be in. Agreed. > > And introducing band aids is not going improve the above situation, > more likely it will prolong it even further. Sounds like “Perfect is the enemy of good” to me: you’re looking for a perfect hypothetical solution, whereas we have a known-working low risk fix for a real problem. Could we find a solution where medium-/long-term, the code in question is improved, perhaps via a Summer Of Code project or similar community efforts, but until then, we apply the patch at hand? As I mentioned, I think adding min/max limits can be useful regardless of how the heuristic itself changes. If that turns out to be incorrect or undesired, we can still turn the knobs into a no-op, if removal isn’t an option. Thanks Best regards Michael
