Messages in this thread | | | Date | Tue, 9 May 2023 22:54:17 +0200 | From | luca abeni <> | Subject | Re: [PATCH 1/2] sched/deadline: accurate reclaim bandwidth for GRUB |
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On Tue, 9 May 2023 22:48:29 +0200 luca abeni <luca.abeni@santannapisa.it> wrote:
> Hi, > > On Tue, 9 May 2023 15:29:21 -0400 > Vineeth Remanan Pillai <vineeth@bitbyteword.org> wrote: > [...] > > > Is this understanding correct? > > Yes, the above two details are correct. In addition to that, I think > > the existing equation had a small bug: > > GRUB paper says, running time is depreciated as > > "dq = -U dt" where U is running_bw. > > This is assuming that the whole cpu bandwidth could be reclaimed. > > But in our case, we cap at Umax. So the equation should be > > "dq = -(U/Umax) dt" > > Yes, this is the approximation I was mentioning... Instead of using a > division, I approximated it with a different equation using a sum.
Sorry, ignore this comment (and the following); I misinterpreted the code (and my old notes).
I do not understand why the "max{}" doe not work well, I need to double think about it.
Luca
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