From: Borislav Petkov <bp@alien8.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Luck, Tony" <tony.luck@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Arvind Sankar <nivedita@alum.mit.edu>,
"Christopherson, Sean J" <sean.j.christopherson@intel.com>,
Ingo Molnar <mingo@kernel.org>,
"Yu, Fenghua" <fenghua.yu@intel.com>,
Ingo Molnar <mingo@redhat.com>, H Peter Anvin <hpa@zytor.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
"Shankar, Ravi V" <ravi.v.shankar@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>
Subject: Re: [PATCH v15] x86/split_lock: Enable split lock detection by kernel
Date: Sat, 25 Jan 2020 21:33:12 +0100 [thread overview]
Message-ID: <20200125203312.GE4369@zn.tnic> (raw)
In-Reply-To: <20200125201221.GZ11457@worktop.programming.kicks-ass.net>
On Sat, Jan 25, 2020 at 09:12:21PM +0100, Peter Zijlstra wrote:
> > Blame PeterZ for that. For now I'd like to add the duplicate inline function
> > and then clean up by putting it into some header file (and maybe hunting down
> > other places where it could be used).
Sounds like a good plan.
> Yeah, I copy/paste cobbled that together. I figured it was easier to
> 'borrow' something that worked and adapt it than try and write
> something new in a hurry.
Yeah.
> > Also some PeterZ code. As the comment implies we really shouldn't be able
> > to get here. This whole function should only be called on CPU models that
> > support the MSR ... but PeterZ is defending against the situation that sometimes
> > there are special SKUs with the same model number (since we may be here because
> > of an x86_match_cpu() hit, rather than the architectural enumeration check).
>
> My thinking was Virt, virt likes to mess up all msr expectations.
My only worry is to have it written down why we're doing this so that it
can be changed/removed later, when we've forgotten all about split lock.
Because pretty often we look at a comment-less chunk of code and wonder,
"why the hell did we add this in the first place."
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-01-25 20:33 UTC|newest]
Thread overview: 145+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-21 0:53 [PATCH v10 0/6] Enable split lock detection for real time and debug Fenghua Yu
2019-11-21 0:53 ` [PATCH v10 1/6] x86/msr-index: Add two new MSRs Fenghua Yu
2019-11-21 0:53 ` [PATCH v10 2/6] x86/cpufeatures: Enumerate the IA32_CORE_CAPABILITIES MSR Fenghua Yu
2019-11-21 0:53 ` [PATCH v10 3/6] x86/split_lock: Enumerate split lock detection by " Fenghua Yu
2019-11-21 0:53 ` [PATCH v10 4/6] x86/split_lock: Enumerate split lock detection if the IA32_CORE_CAPABILITIES MSR is not supported Fenghua Yu
2019-11-21 22:07 ` Andy Lutomirski
2019-11-22 0:37 ` Fenghua Yu
2019-11-22 2:13 ` Andy Lutomirski
2019-11-22 9:46 ` Peter Zijlstra
2019-11-21 0:53 ` [PATCH v10 5/6] x86/split_lock: Handle #AC exception for split lock Fenghua Yu
2019-11-21 22:10 ` Andy Lutomirski
2019-11-21 23:14 ` Fenghua Yu
2019-11-21 23:12 ` Andy Lutomirski
2019-11-21 0:53 ` [PATCH v10 6/6] x86/split_lock: Enable split lock detection by kernel parameter Fenghua Yu
2019-11-21 6:04 ` Ingo Molnar
2019-11-21 13:01 ` Peter Zijlstra
2019-11-21 13:15 ` Peter Zijlstra
2019-11-21 21:51 ` Luck, Tony
2019-11-21 22:24 ` Andy Lutomirski
2019-11-21 22:29 ` Luck, Tony
2019-11-21 23:18 ` Andy Lutomirski
2019-11-21 23:53 ` Fenghua Yu
2019-11-22 1:52 ` Sean Christopherson
2019-11-22 2:21 ` Andy Lutomirski
2019-11-22 2:39 ` Xiaoyao Li
2019-11-22 2:57 ` Andy Lutomirski
2019-11-21 23:55 ` Luck, Tony
2019-11-22 0:55 ` Luck, Tony
2019-11-22 10:08 ` Peter Zijlstra
2019-11-21 16:14 ` Fenghua Yu
2019-11-21 17:14 ` Ingo Molnar
2019-11-21 17:35 ` Peter Zijlstra
2019-11-21 17:12 ` Ingo Molnar
2019-11-21 17:34 ` Luck, Tony
2019-11-22 10:51 ` Peter Zijlstra
2019-11-22 15:27 ` Peter Zijlstra
2019-11-22 17:22 ` Luck, Tony
2019-11-22 20:23 ` Peter Zijlstra
2019-11-22 18:02 ` Luck, Tony
2019-11-22 20:23 ` Peter Zijlstra
2019-11-22 20:42 ` Fenghua Yu
2019-11-22 21:25 ` Andy Lutomirski
2019-12-12 8:57 ` Peter Zijlstra
2019-12-12 18:52 ` Luck, Tony
2019-12-12 19:46 ` Luck, Tony
2019-12-12 20:01 ` Andy Lutomirski
2019-12-16 16:21 ` David Laight
2019-11-22 18:44 ` Sean Christopherson
2019-11-22 20:30 ` Peter Zijlstra
2019-11-23 0:30 ` Luck, Tony
2019-11-25 16:13 ` Sean Christopherson
2019-12-02 18:20 ` Luck, Tony
2019-12-12 8:59 ` Peter Zijlstra
2020-01-10 19:24 ` [PATCH v11] x86/split_lock: Enable split lock detection by kernel Luck, Tony
2020-01-14 5:55 ` Sean Christopherson
2020-01-15 22:27 ` Luck, Tony
2020-01-15 22:57 ` Sean Christopherson
2020-01-15 23:48 ` Luck, Tony
2020-01-22 18:55 ` [PATCH v12] " Luck, Tony
2020-01-22 19:04 ` Borislav Petkov
2020-01-22 20:03 ` Luck, Tony
2020-01-22 20:55 ` Borislav Petkov
2020-01-22 22:42 ` Arvind Sankar
2020-01-22 22:52 ` Arvind Sankar
2020-01-22 23:24 ` Luck, Tony
2020-01-23 0:45 ` Arvind Sankar
2020-01-23 1:23 ` Luck, Tony
2020-01-23 4:21 ` Arvind Sankar
2020-01-23 17:15 ` Luck, Tony
2020-01-23 3:53 ` [PATCH v13] " Luck, Tony
2020-01-23 4:45 ` Arvind Sankar
2020-01-23 23:16 ` [PATCH v14] " Luck, Tony
2020-01-24 21:36 ` Thomas Gleixner
2020-01-25 2:47 ` [PATCH v15] " Luck, Tony
2020-01-25 10:44 ` Borislav Petkov
2020-01-25 19:55 ` Luck, Tony
2020-01-25 20:12 ` Peter Zijlstra
2020-01-25 20:33 ` Borislav Petkov [this message]
2020-01-25 21:42 ` Luck, Tony
2020-01-25 22:17 ` Borislav Petkov
2020-01-25 20:29 ` Borislav Petkov
2020-01-25 13:41 ` Thomas Gleixner
2020-01-25 22:07 ` [PATCH v16] " Luck, Tony
2020-01-25 22:43 ` Mark D Rustad
2020-01-25 23:10 ` Luck, Tony
2020-01-26 17:27 ` Mark D Rustad
2020-01-26 20:05 ` [PATCH v17] " Luck, Tony
2020-01-29 12:31 ` Thomas Gleixner
2020-01-29 15:24 ` [tip: x86/cpu] " tip-bot2 for Peter Zijlstra (Intel)
2020-02-03 20:41 ` [PATCH v17] " Sean Christopherson
2020-02-06 0:49 ` [PATCH] x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR Luck, Tony
2020-02-06 1:18 ` Andy Lutomirski
2020-02-06 16:46 ` Luck, Tony
2020-02-06 19:37 ` Andy Lutomirski
2020-03-03 19:22 ` Sean Christopherson
2020-02-04 0:04 ` [PATCH v17] x86/split_lock: Enable split lock detection by kernel Sean Christopherson
2020-02-04 12:52 ` Thomas Gleixner
2020-01-26 0:34 ` [PATCH v16] " Andy Lutomirski
2020-01-26 20:01 ` Luck, Tony
2020-01-25 21:25 ` [PATCH v15] " Arvind Sankar
2020-01-25 21:50 ` Luck, Tony
2020-01-25 23:51 ` Arvind Sankar
2020-01-26 2:52 ` Luck, Tony
2020-01-27 2:05 ` Tony Luck
2020-01-27 8:04 ` Peter Zijlstra
2020-01-27 8:36 ` Peter Zijlstra
2020-01-27 17:35 ` Luck, Tony
2020-01-27 8:02 ` Peter Zijlstra
2019-12-13 0:09 ` [PATCH v11] x86/split_lock: Enable split lock detection by kernel parameter Tony Luck
2019-12-13 0:16 ` Luck, Tony
2019-11-21 17:43 ` [PATCH v10 6/6] " David Laight
2019-11-21 17:51 ` Andy Lutomirski
2019-11-21 18:53 ` Fenghua Yu
2019-11-21 19:01 ` Andy Lutomirski
2019-11-21 20:25 ` Fenghua Yu
2019-11-21 20:19 ` Peter Zijlstra
2019-11-21 19:46 ` Peter Zijlstra
2019-11-21 20:25 ` Peter Zijlstra
2019-11-21 21:22 ` Andy Lutomirski
2019-11-22 9:25 ` Peter Zijlstra
2019-11-22 17:48 ` Luck, Tony
2019-11-22 20:31 ` Peter Zijlstra
2019-11-22 21:23 ` Andy Lutomirski
2019-12-11 17:52 ` Peter Zijlstra
2019-12-11 18:12 ` Andy Lutomirski
2019-12-11 22:34 ` Peter Zijlstra
2019-12-12 19:40 ` Andy Lutomirski
2019-12-16 9:59 ` David Laight
2019-12-16 17:22 ` Andy Lutomirski
2019-12-16 17:45 ` David Laight
2019-12-16 18:06 ` Andy Lutomirski
2019-12-17 10:03 ` David Laight
2019-12-11 18:44 ` Luck, Tony
2019-12-11 22:39 ` Peter Zijlstra
2019-12-12 10:36 ` David Laight
2019-12-12 13:04 ` Peter Zijlstra
2019-12-12 16:02 ` Andy Lutomirski
2019-12-12 16:23 ` David Laight
2019-12-12 16:29 ` David Laight
2019-11-21 19:56 ` Peter Zijlstra
2019-11-21 21:01 ` Andy Lutomirski
2019-11-22 9:36 ` Peter Zijlstra
2019-11-22 9:46 ` David Laight
2019-11-22 20:32 ` Peter Zijlstra
2019-11-21 8:00 ` Peter Zijlstra
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