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charset=us-ascii Content-Disposition: inline In-Reply-To: <20250620113745.6833bccb@luca64> On 20/06/25 11:37, luca abeni wrote: > Hi Juri, > > On Fri, 20 Jun 2025 11:29:52 +0200 > Juri Lelli wrote: > [...] > > I have been playing a little more with this and noticed (by chance) > > that after writing a value on sched_rt_runtime_us (even the 950000 > > default) this seem to 'work' - I don't see deadline misses anymore. > > > > I thus have moved my attention to GRUB related per-cpu variables [1] > > and noticed something that looks fishy with extra_bw: after boot and > > w/o any DEADLINE tasks around (other than dl_servers) all dl_rqs have > > different values [2]. E.g., > > > > extra_bw : (u64)447170 > > extra_bw : (u64)604454 > [...] > > So, this might be one thing to look at, but I am honestly still > > confused by why we have weird numbers as the above after boot. Also a > > bit confused by the actual meaning and purpose of the 5 GRUB > > variables we have to deal with. > > Sorry about that... I was under the impression they were documented in > some comments, but I might be wrong... No worries! I am also culpable, as I did test and review the patches. :) extra_bw in particular I believe can benefit from a bit of attention. > > Luca, Vineeth (for the recent introduction of max_bw), maybe we could > > take a step back and re-check (and maybe and document better :) what > > each variable is meant to do and how it gets updated? > > I am not sure about the funny values initially assigned to these > variables, but I can surely provide some documentation about what these > variables represent... I am going to look at this and I'll send some > comments or patches. Thanks a lot! I am also continuing to dig.