From: "H. Peter Anvin" <hpa@zytor.com>
To: "Luck, Tony" <tony.luck@intel.com>,
"Mehta, Sohil" <sohil.mehta@intel.com>,
"x86@kernel.org" <x86@kernel.org>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Uros Bizjak <ubizjak@gmail.com>,
Sandipan Das <sandipan.das@amd.com>,
Sean Christopherson <seanjc@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Vegard Nossum <vegard.nossum@oracle.com>,
Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
Nikolay Borisov <nik.borisov@suse.com>,
Eric Biggers <ebiggers@google.com>,
"Li, Xin3" <xin3.li@intel.com>,
"Shishkin, Alexander" <alexander.shishkin@intel.com>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] x86/cpufeature: Add feature dependency checks
Date: Wed, 30 Oct 2024 18:59:02 -0700 [thread overview]
Message-ID: <84E58634-C57A-4841-BD52-2E15BD9DF592@zytor.com> (raw)
In-Reply-To: <SJ1PR11MB60836BD27B436E3E8B404AA2FC542@SJ1PR11MB6083.namprd11.prod.outlook.com>
On October 30, 2024 4:44:59 PM PDT, "Luck, Tony" <tony.luck@intel.com> wrote:
>> +void filter_feature_dependencies(struct cpuinfo_x86 *c)
>> +{
>> + const struct cpuid_dep *d;
>> +
>> + for (d = cpuid_deps; d->feature; d++) {
>> + if (cpu_has(c, d->feature) && !cpu_has(c, d->depends))
>> + do_clear_cpu_cap(c, d->feature);
>> + }
>> +}
>
>The dependency check found something very wrong. Should there be
>a pr_warn() to give some clue that Linux papered over this problem?
>
>-Tony
>
Not necessarily. Linux is free to impose restrictions that don't necessarily match the hardware thermometers. For example, letting LAM depend on LASS.
prev parent reply other threads:[~2024-10-31 2:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-30 23:31 Sohil Mehta
2024-10-30 23:39 ` Dave Hansen
2024-10-30 23:44 ` Luck, Tony
2024-10-30 23:57 ` Sohil Mehta
2024-10-31 1:59 ` H. Peter Anvin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=84E58634-C57A-4841-BD52-2E15BD9DF592@zytor.com \
--to=hpa@zytor.com \
--cc=alexander.shishkin@intel.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=ebiggers@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=nik.borisov@suse.com \
--cc=pawan.kumar.gupta@linux.intel.com \
--cc=peterz@infradead.org \
--cc=sandipan.das@amd.com \
--cc=seanjc@google.com \
--cc=sohil.mehta@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=ubizjak@gmail.com \
--cc=vegard.nossum@oracle.com \
--cc=x86@kernel.org \
--cc=xin3.li@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®