On Thu Jul 31, 2025 at 3:56 PM CEST, Thomas Lamprecht wrote: > On Thu, 31 Jul 2025 15:51:42 +0200, Friedrich Weber wrote: >> Pressure stall information are actually in percent. This is not >> mentioned explicitly in the documentation, but e.g. in the kernel >> source [1]: >> >> > The percentage of wall clock time spent in those compound stall >> > states gives pressure numbers between 0 and 100 for each resource, >> > where the SOME percentage indicates workload slowdowns and the FULL >> > percentage indicates reduced CPU utilization: >> > >> > %SOME = time(SOME) / period >> > %FULL = time(FULL) / period >> >> [...] > > This was a bit strange for me, I seemingly ingrained some wrong knownledge > when > getting first exposed to PSI when that was a new thing back in 2019 or so, > either the docs where worded a bit differently or I just read a bit to much > into the wording (more likely), anyhow thanks for clarifying this, one thing > that I'm still wondering is this then percent for real (i.e. * 100 already) or > a ratio? Or would we need to do *= 100 scaling? > > Anyway, as this restores the status quo with rationale it's already an > improvement as is, so: Applied, thanks!
if i remember correctly and read the kernel documentation correctly, this is proper percent (%) [1]. so no additional multiplying necessary. > The ratios (in %) are tracked as recent trends over ten, sixty, and > three hundred second windows, which gives insight into short term > events as well as medium and long term trends. also did i quick check here on my machine (by compiling pbs): > ==> /proc/pressure/cpu <== > some avg10=10.63 avg60=3.66 avg300=0.87 total=54165853 so the `avg10=10.63` should be percent. [1]: https://www.kernel.org/doc/html/latest/accounting/psi.html > > [1/1] ui: RRD graphs: display PSI as percent > commit: 2753e104a1e6effa4a0ae995f13636a02f3557af > > > _______________________________________________ > pve-devel mailing list > pve-devel@lists.proxmox.com > https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
