Messages in this thread |  | | Date | Sun, 11 Nov 2001 13:18:48 -0800 (PST) | From | Davide Libenzi <> | Subject | Re: [patch] scheduler cache affinity improvement for 2.4 kernels |
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On Fri, 9 Nov 2001, Ingo Molnar wrote:
> > On Thu, 8 Nov 2001, Mike Fedyk wrote: > > > It remains to be proven whether the coarser scheduling approach > > (Ingo's) will actually help when looking at cache properties.... [...] > > have you seen the numbers/measurements i posted in my original email? 3% > kernel compile speedup on an 'idle' 8-way system, 7% compilation speedup > with HZ=1024 and background networking load on a 1-way system.
Ingo, i'm giving the timer_ticks patch a try in my proposed scheduler coz i like the idea of skipping the if inside goodness(), and i can do this safely because inside the proposed scheduler i don't have any cross CPU goodnesses ( no "if (p->processor != this_cpu) weight -= p->timer_ticks;" ). I made a change to it anyway, that is adding a water-mark in the decay behavior ( timer.c ). When counter is above this watermark ( currently 20 ) the counter decay as usual while if counter <= watermark, ticks accumulates in timer_ticks. This solution keeps the same good behavior for CPU bound tasks while it gives a "human"/current decay to tasks that has got a lot of counter accumulation inside the recalc loop ( I/O bound ).
- Davide
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