Date: Fri, 23 Sep 2022 22:58:39 -0700 From: Kevin Oberman <rkoberman@gmail.com> To: Amar Takhar <verm@darkbeer.org> Cc: questions@freebsd.org Subject: Re: Disabling CPUs Message-ID: <CAN6yY1voZgRRc8hCe_hVXusdoeQrt%2B=shO28FbiUNMzK_5F2hQ@mail.gmail.com> In-Reply-To: <20220922180626.GB79310@darkbeer.org> References: <CAN6yY1s=ds_=yWsEWtVfoXchD5XXqU5uPw6bdFNW%2BdaU6t491A@mail.gmail.com> <20220922180626.GB79310@darkbeer.org>
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--000000000000c4256905e965fd2f Content-Type: text/plain; charset="UTF-8" Thanks, Amar! I'll give this a try tomorrow. Have you compared performance using only P cores vs. only E cores? My testing (using only cpuset) compiles C faster with 8 E cores than 2 P cores (4 "CPUs"). By any chance have you run a VirtualBox VM? I have found that a Windows 10 VM loads, but the system panics as soon as the VM starts running. I have a couple of things to try that could be triggering the problem. Notably, I have 3D HW acceleration enabled and, since it is not available with scfb, it's a possible cause. I'm getting tired of trailblazing! My current laptop did not have a working Wii interface until iwlwifi. I had een almost no comments on CURRENT, soi I had no idea how much trouble I was gettig into. On Thu, Sep 22, 2022 at 11:06 AM Amar Takhar <verm@darkbeer.org> wrote: > On 2022-09-21 19:05 -0700, Kevin Oberman wrote: > > I am looking to disable all 8 E-cores on my Alder Lake system to prevent > > repeated crashes. The man page has an example of this: > > Modify the cpuset all threads are in by default to contain only the > first 4 > > CPUs, leaving the rest idle: > > cpuset -l 0-3 -s 1 > > I did this, but in subsequent port build, all 12 "CPUs" were running at > 100%. > > Am I missing something? Maybe use -p 1" instead of "-s 1". > > > > I also found suggestions to use "hint.lapic.N.disabled", but teh lines > that > > were supposed to be in dmesg and the messages log were not present. I am > > baffled, but really need to do something to stop the crashes currently > > impacting Alder Lake systems. > > You need to do it in BIOS it's the only way. Unfortunately even if you do > it > within FreeBSD it still sees those cores just doesn't schedule them it > causes an > issue somewhere regardless I did try to not schedule anything to them. > > If you don't see any specific option to disable E-cores you'll need to > disable > them individually. As far as I know the E-cores are always the last cores > in > the list. > > Any Alder Lake BIOS should have the setting. > > > Amar. > > -- Kevin Oberman, Part time kid herder and retired Network Engineer E-mail: rkoberman@gmail.com PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683 --000000000000c4256905e965fd2f Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-family:tahoma,s= ans-serif;font-size:small">Thanks, Amar! I'll give this a try tomorrow.= </div><div class=3D"gmail_default" style=3D"font-family:tahoma,sans-serif;f= ont-size:small"><br></div><div class=3D"gmail_default" style=3D"font-family= :tahoma,sans-serif;font-size:small">Have you compared performance using onl= y P cores vs. only E cores? My testing (using only cpuset) compiles C faste= r with 8 E cores than 2 P cores (4 "CPUs").<br></div><div class= =3D"gmail_default" style=3D"font-family:tahoma,sans-serif;font-size:small">= <br></div><div class=3D"gmail_default" style=3D"font-family:tahoma,sans-ser= if;font-size:small">By any chance have you run a VirtualBox VM? I have foun= d that a Windows 10 VM loads, but the system panics as soon as the VM start= s running. I have a couple of things to try that could be triggering the pr= oblem. Notably, I have 3D HW acceleration enabled and, since it is not avai= lable with scfb, it's a possible cause.</div><div class=3D"gmail_defaul= t" style=3D"font-family:tahoma,sans-serif;font-size:small"><br></div><div c= lass=3D"gmail_default" style=3D"font-family:tahoma,sans-serif;font-size:sma= ll">I'm getting tired of trailblazing! My current laptop did not have a= working Wii interface until iwlwifi. I had een almost no comments on CURRE= NT, soi I had no idea how much trouble I was gettig into.<br></div></div><b= r><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Thu, = Sep 22, 2022 at 11:06 AM Amar Takhar <<a href=3D"mailto:verm@darkbeer.or= g">verm@darkbeer.org</a>> wrote:<br></div><blockquote class=3D"gmail_quo= te" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204= );padding-left:1ex">On 2022-09-21 19:05 -0700, Kevin Oberman wrote:<br> > I am looking to disable all 8 E-cores on my Alder Lake system to preve= nt<br> > repeated crashes. The man page has an example of this:<br> > Modify the cpuset all threads are in by default to contain only the fi= rst 4<br> > CPUs, leaving the rest idle:<br> > =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0cpuset -l 0-3 -s 1<br> > I did this, but in subsequent port build, all 12 "CPUs" were= running at 100%.<br> > Am I missing something? Maybe use -p 1" instead of "-s 1&quo= t;.<br> > <br> > I also found suggestions to use "hint.lapic.N.disabled", but= teh lines that<br> > were supposed to be in dmesg and the messages log were not present. I = am<br> > baffled, but really need to do something to stop the crashes currently= <br> > impacting Alder Lake systems.<br> <br> You need to do it in BIOS it's the only way.=C2=A0 Unfortunately even i= f you do it <br> within FreeBSD it still sees those cores just doesn't schedule them it = causes an <br> issue somewhere regardless I did try to not schedule anything to them.<br> <br> If you don't see any specific option to disable E-cores you'll need= to disable <br> them individually.=C2=A0 As far as I know the E-cores are always the last c= ores in <br> the list.<br> <br> Any Alder Lake BIOS should have the setting.<br> <br> <br> Amar.<br> <br> </blockquote></div><br clear=3D"all"><br>-- <br><div dir=3D"ltr" class=3D"g= mail_signature"><div dir=3D"ltr"><div><div dir=3D"ltr"><div><div dir=3D"ltr= "><div><div dir=3D"ltr">Kevin Oberman, Part time kid herder and retired Net= work Engineer<br>E-mail: <a href=3D"mailto:rkoberman@gmail.com" target=3D"_= blank">rkoberman@gmail.com</a><br></div><div>PGP Fingerprint: D03FB98AFA78E= 3B78C1694B318AB39EF1B055683</div></div></div></div></div></div></div></div> --000000000000c4256905e965fd2f--
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