From: Tim Chen <tim.c.chen@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Kosina <jikos@kernel.org>,
Tom Lendacky <thomas.lendacky@amd.com>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
David Woodhouse <dwmw@amazon.co.uk>,
Andi Kleen <ak@linux.intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Casey Schaufler <casey.schaufler@intel.com>,
Asit Mallick <asit.k.mallick@intel.com>,
Arjan van de Ven <arjan@linux.intel.com>,
Jon Masters <jcm@redhat.com>, Waiman Long <longman9394@gmail.com>,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [Patch v4 08/18] sched: Deprecate sched_smt_present and use cpu_smt_enabled static key
Date: Fri, 9 Nov 2018 14:08:43 -0800 [thread overview]
Message-ID: <e6b4af48-d848-8567-5927-745bbf6a388b@linux.intel.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1811031914470.3160@nanos.tec.linutronix.de>
Thomas,
>
>> The cpu_smt_enabled static key serves identical purpose as cpu_smt_enabled
>
> That doesn't make any sense.
>
>> to enable SMT specific code.
>>
>> This patch replaces sched_smt_present in the scheduler with
>> cpu_smt_enabled and deprecate sched_smt_present.
>
> It's not deprecating it, it's replacing and removing it and thereby
> breaking all architectures which select SCHED_SMT except x86.
But the cpu_smt_enabled key is not x86 specific. It is set and
defined in generic kernel/cpu.c and include/linux/cpu.h and available
for all architectures.
Why would it break other architectures? I am missing something?
Thanks.
Tim
next prev parent reply other threads:[~2018-11-09 22:08 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-30 18:49 [Patch v4 00/18] Provide process property based options to enable Spectre v2 userspace-userspace protection* Tim Chen
2018-10-30 18:49 ` [Patch v4 01/18] x86/speculation: Clean up spectre_v2_parse_cmdline() Tim Chen
2018-10-30 18:49 ` [Patch v4 02/18] x86/speculation: Remove unnecessary ret variable in cpu_show_common() Tim Chen
2018-10-30 18:49 ` [Patch v4 03/18] x86/speculation: Reorganize cpu_show_common() Tim Chen
2018-11-03 18:07 ` Thomas Gleixner
2018-11-05 19:12 ` Tim Chen
2018-11-05 19:17 ` Thomas Gleixner
2018-10-30 18:49 ` [Patch v4 04/18] x86/speculation: Add X86_FEATURE_USE_IBRS_ENHANCED Tim Chen
2018-10-30 18:49 ` [Patch v4 05/18] x86/speculation: Disable STIBP when enhanced IBRS is in use Tim Chen
2018-10-30 18:49 ` [Patch v4 06/18] smt: Create cpu_smt_enabled static key for SMT specific code Tim Chen
2018-10-30 18:49 ` [Patch v4 07/18] x86/smt: Convert cpu_smt_control check to cpu_smt_enabled static key Tim Chen
2018-11-03 18:29 ` Thomas Gleixner
2018-11-08 1:43 ` Tim Chen
2018-11-08 11:18 ` Thomas Gleixner
2018-10-30 18:49 ` [Patch v4 08/18] sched: Deprecate sched_smt_present and use " Tim Chen
2018-11-03 18:20 ` Thomas Gleixner
2018-11-09 22:08 ` Tim Chen [this message]
2018-10-30 18:49 ` [Patch v4 09/18] x86/speculation: Rename SSBD update functions Tim Chen
2018-10-30 18:49 ` [Patch v4 10/18] x86/speculation: Reorganize speculation control MSRs update Tim Chen
2018-10-30 18:49 ` [Patch v4 11/18] x86/speculation: Update comment on TIF_SSBD Tim Chen
2018-10-30 18:49 ` [Patch v4 12/18] x86: Group thread info flags by functionality Tim Chen
2018-10-30 18:49 ` [Patch v4 13/18] security: Update security level of a process when modifying its dumpability Tim Chen
2018-10-30 20:57 ` Schaufler, Casey
2018-10-30 21:30 ` Tim Chen
2018-10-30 21:53 ` Schaufler, Casey
2018-10-30 18:49 ` [Patch v4 14/18] x86/speculation: Turn on or off STIBP according to a task's TIF_STIBP Tim Chen
2018-10-30 18:49 ` [Patch v4 15/18] x86/speculation: Add Spectre v2 app to app protection modes Tim Chen
2018-10-30 18:49 ` [Patch v4 16/18] x86/speculation: Enable STIBP to protect security sensitive tasks Tim Chen
2018-10-30 21:07 ` Schaufler, Casey
2018-10-30 21:34 ` Tim Chen
2018-10-30 22:02 ` Schaufler, Casey
2018-10-30 18:49 ` [Patch v4 17/18] x86/speculation: Update SPEC_CTRL MSRs of remote CPUs Tim Chen
2018-11-04 19:49 ` Thomas Gleixner
2018-11-05 22:02 ` Tim Chen
2018-11-05 23:04 ` Thomas Gleixner
2018-11-05 23:59 ` Tim Chen
2018-11-06 7:46 ` Thomas Gleixner
2018-11-07 0:18 ` Tim Chen
2018-11-07 18:33 ` Waiman Long
2018-11-07 23:15 ` Tim Chen
2018-11-07 23:03 ` Thomas Gleixner
2018-11-08 0:22 ` Tim Chen
2018-10-30 18:49 ` [Patch v4 18/18] x86/speculation: Create PRCTL interface to restrict indirect branch speculation Tim Chen
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