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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[-- Attachment #1 --] 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 [-- Attachment #2 --] <div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">Thanks, Amar! I'll give this a try tomorrow.</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">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").<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">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.</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">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.<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 22, 2022 at 11:06 AM Amar Takhar <<a href="mailto:verm@darkbeer.org">verm@darkbeer.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="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 prevent<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 first 4<br> > CPUs, leaving the rest idle:<br> > cpuset -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".<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. Unfortunately even if 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. As far as I know the E-cores are always the last cores in <br> the list.<br> <br> Any Alder Lake BIOS should have the setting.<br> <br> <br> Amar.<br> <br> </blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">Kevin Oberman, Part time kid herder and retired Network Engineer<br>E-mail: <a href="mailto:rkoberman@gmail.com" target="_blank">rkoberman@gmail.com</a><br></div><div>PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683</div></div></div></div></div></div></div></div>home | help
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