Man, that's what I was hoping for, great answer!!! Thnx
-- R. Sent with Proton Mail secure email. On Wednesday, September 2nd, 2026 at 2:24 PM, Brian Brombacher <[email protected]> wrote: > Thanks for the dmesg. Yes you have 2 performance cores (with SMT enabled > makes 4) and 8 efficient cores. I would use hw.blockcpu=L so you get to use > all those E cores and don’t bottleneck your laptop to just 2 P cores. The P > to E ratio is 76% for turbo frequency (5 GHz vs 3.8 GHz) and 64% for base > frequency (1.4 GHz vs 900 MHz). That’s not too bad and you probably won’t > notice anything. > > > On Sep 2, 2026, at 2:09 PM, Ronny Machado <[email protected]> wrote: > > > > Thanks, that's what I was asking for...anyway, dmesg attached justi in > > case. > > > > -- > > > > R. > > > > Sent with Proton Mail secure email. > > > >> On Wednesday, September 2nd, 2026 at 1:56 PM, Brian Brombacher > >> <[email protected]> wrote: > >> > >> Including a dmesg would be helpful here. > >> > >> My guess is you have a CPU with 4 performance/smt cores and 8 efficient > >> cores. Setting hw.blockcpu=E means to block the use of the 8 efficient > >> cores. Setting hw.blockcpu=L means to block lethargic cores, which you > >> have zero of, so the end result is you get access to all 12 cores on your > >> CPU. > >> > >> It all depends on what you want to achieve. If you don’t mind having > >> processes move between performance and efficient cores, then blocking L or > >> none would be fine. If you want to ensure deterministic processing power, > >> then block E or EL (again, you have no lethargic cores so it doesn’t > >> matter if you include L or not). If your laptop runs fine with > >> hw.blockcpu=L, then use that. Again a dmesg would help us determine what > >> kind of processor you have and therefore how severe the performance > >> degradation is between P and E cores. > >> > >> > >>>> On Sep 2, 2026, at 1:20 PM, Ronny Machado <[email protected]> > >>>> wrote: > >>> > >>> > >>> Okay, this may be a silly question, since 7.9 (which I've been using > >>> since day one) I still don't quite understand the advantages of > >>> hw.blockcpu. > >>> > >>> In announcements: > >>> > >>> "Various kernel improvements: > >>> Introduced a mechanism to manage CPU cores with different speeds in the > >>> scheduler. The sysctl(8) variable "hw.blockcpu" takes a sequence of 4 > >>> letters: S (for SMT), P (regular performance CPU), E (efficient CPU, > >>> generally 80% to 50% as fast), and L (lethargic CPU) which are even > >>> slower. Set this to select CPUs to kick out of the scheduler (SL by > >>> default). Currently works on amd64 and arm64." > >>> > >>> Actually I'm running hw.blockcpu=E, and I see 4 cpus, in "L" I see > >>> 12...So, as I said, I still don't quite understand the logic about it, > >>> can someone be so kind to explain that for me? > >>> > >>> In "E" conf, my laptop runs smoothly, VMD and all, in "L" the same... :( > >>> > >>> Thanks in advance > >>> > >>> > >>> -- > >>> > >>> Ronny Machado C. > >>> > >>> > >>> IT Consultant > >>> HP-UX Certified Systems Administrator > >>> Oracle Linux Certified Implementation Specialist > >>> Oracle MySQL Enterprise Certified Implementation Specialist > >>> > >>> https://sysops.cl > >>> +56 9 7519 9262 > >>> > >>> Sent with Proton Mail secure email. > >>> > >> > > <dmesg.txt> > >
