From: Vineeth Pillai <viremana@linux.microsoft.com>
To: Joel Fernandes <joel@joelfernandes.org>,
Dario Faggioli <dfaggioli@suse.com>
Cc: "Thomas Gleixner" <tglx@linutronix.de>,
"Julien Desfossez" <jdesfossez@digitalocean.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Tim Chen" <tim.c.chen@linux.intel.com>,
"Aaron Lu" <aaron.lwe@gmail.com>,
"Aubrey Li" <aubrey.intel@gmail.com>,
"Dhaval Giani" <dhaval.giani@oracle.com>,
"Chris Hyser" <chris.hyser@oracle.com>,
"Nishanth Aravamudan" <naravamudan@digitalocean.com>,
"Ingo Molnar" <mingo@kernel.org>, "Paul Turner" <pjt@google.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
"Frederic Weisbecker" <fweisbec@gmail.com>,
"Kees Cook" <keescook@chromium.org>,
"Greg Kerr" <kerrnel@google.com>, "Phil Auld" <pauld@redhat.com>,
"Valentin Schneider" <valentin.schneider@arm.com>,
"Mel Gorman" <mgorman@techsingularity.net>,
"Pawan Gupta" <pawan.kumar.gupta@linux.intel.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
vineeth@bitbyteword.org, "Chen Yu" <yu.c.chen@intel.com>,
"Christian Brauner" <christian.brauner@ubuntu.com>,
"Agata Gruza" <agata.gruza@intel.com>,
"Antonio Gomez Iglesias" <antonio.gomez.iglesias@intel.com>,
graf@amazon.com, konrad.wilk@oracle.com,
"Steven Rostedt" <rostedt@goodmis.org>,
"Patrick Bellasi" <derkling@google.com>,
"benbjiang(蒋彪)" <benbjiang@tencent.com>,
"Aubrey Li" <aubrey.li@linux.intel.com>,
"Tim Chen" <tim.c.chen@intel.com>,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: Re: [RFC PATCH v7 17/23] kernel/entry: Add support for core-wide protection of kernel-mode
Date: Thu, 3 Sep 2020 07:05:25 -0400 [thread overview]
Message-ID: <9471f752-1a30-d46f-be75-d3d433980385@linux.microsoft.com> (raw)
In-Reply-To: <CAEXW_YRQiC_0edO5L2vVmL0NcfeZaRt4WYoyrcKmzbFcQP3PvA@mail.gmail.com>
On 9/3/20 12:34 AM, Joel Fernandes wrote:
>>
>> Indeed! For at least two reasons, IMO:
>>
>> 1) what Thomas is saying already. I.e., even on a CPU which has HT but
>> is not affected by any of the (known!) speculation issues, one may want
>> to use Core Scheduling _as_a_feature_. For instance, for avoiding
>> threads from different processes, or vCPUs from different VMs, sharing
>> cores (e.g., for better managing their behavior/performance, or for
>> improved fairness of billing/accounting). And in this case, this
>> mechanism for protecting the kernel from the userspace on the other
>> thread may not be necessary or interesting;
> Agreed. So then I should really make this configurable and behind a
> sysctl then. I'll do that.
We already have the patch to wrap this feature in a build time and
boot time option:
https://lwn.net/ml/linux-kernel/9cd9abad06ad8c3f35228afd07c74c7d9533c412.1598643276.git.jdesfossez@digitalocean.com/
I could not get to a safe way to make it a runtime tunable at the time
of posting this series, but I think it should also be possible.
Thanks,
Vineeth
next prev parent reply other threads:[~2020-09-03 15:23 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-28 19:51 [RFC PATCH v7 00/23] Core scheduling v7 Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 01/23] sched: Wrap rq::lock access Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 02/23] sched: Introduce sched_class::pick_task() Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 03/23] sched: Core-wide rq->lock Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 04/23] sched/fair: Add a few assertions Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 05/23] sched: Basic tracking of matching tasks Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 06/23] bitops: Introduce find_next_or_bit Julien Desfossez
2020-09-03 5:13 ` Randy Dunlap
2020-08-28 19:51 ` [RFC PATCH v7 07/23] cpumask: Introduce a new iterator for_each_cpu_wrap_or Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 08/23] sched: Add core wide task selection and scheduling Julien Desfossez
2020-08-28 20:51 ` Peter Zijlstra
2020-08-28 22:02 ` Vineeth Pillai
2020-08-28 22:23 ` Joel Fernandes
2020-08-29 7:47 ` peterz
2020-08-31 13:01 ` Vineeth Pillai
2020-08-31 14:24 ` Joel Fernandes
2020-09-01 3:38 ` Joel Fernandes
2020-09-01 5:10 ` Joel Fernandes
2020-09-01 12:34 ` Vineeth Pillai
2020-09-01 17:30 ` Joel Fernandes
2020-09-01 21:23 ` Vineeth Pillai
2020-09-02 1:11 ` Joel Fernandes
2020-08-28 20:55 ` Peter Zijlstra
2020-08-28 22:15 ` Vineeth Pillai
2020-09-15 20:08 ` Joel Fernandes
2020-08-28 19:51 ` [RFC PATCH v7 09/23] sched/fair: Fix forced idle sibling starvation corner case Julien Desfossez
2020-08-28 21:25 ` Peter Zijlstra
2020-08-28 23:24 ` Vineeth Pillai
2020-08-28 19:51 ` [RFC PATCH v7 10/23] sched/fair: wrapper for cfs_rq->min_vruntime Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 11/23] sched/fair: core wide cfs task priority comparison Julien Desfossez
2020-08-28 21:29 ` Peter Zijlstra
2020-09-17 14:15 ` Vineeth Pillai
2020-09-17 20:39 ` Vineeth Pillai
2020-09-23 1:46 ` Joel Fernandes
2020-09-23 1:52 ` Joel Fernandes
2020-09-25 15:02 ` Joel Fernandes
2020-09-15 21:49 ` chris hyser
[not found] ` <81b208ad-b9e6-bfbf-631e-02e9f75d73a2@linux.intel.com>
2020-09-16 14:24 ` chris hyser
2020-09-16 20:53 ` chris hyser
2020-09-17 1:09 ` Li, Aubrey
2020-08-28 19:51 ` [RFC PATCH v7 12/23] sched: Trivial forced-newidle balancer Julien Desfossez
2020-09-02 7:08 ` Pavan Kondeti
2020-08-28 19:51 ` [RFC PATCH v7 13/23] sched: migration changes for core scheduling Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 14/23] irq_work: Add support to detect if work is pending Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 15/23] entry/idle: Add a common function for activites during idle entry/exit Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 16/23] arch/x86: Add a new TIF flag for untrusted tasks Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 17/23] kernel/entry: Add support for core-wide protection of kernel-mode Julien Desfossez
2020-09-01 15:54 ` Thomas Gleixner
2020-09-01 16:50 ` Joel Fernandes
2020-09-01 20:02 ` Thomas Gleixner
2020-09-02 1:29 ` Joel Fernandes
2020-09-02 7:53 ` Thomas Gleixner
2020-09-02 15:12 ` Joel Fernandes
2020-09-02 16:57 ` Dario Faggioli
2020-09-03 4:34 ` Joel Fernandes
2020-09-03 11:05 ` Vineeth Pillai [this message]
2020-09-03 13:20 ` Thomas Gleixner
2020-09-03 20:30 ` Joel Fernandes
2020-09-03 13:43 ` Dario Faggioli
2020-09-03 20:25 ` Joel Fernandes
2020-08-28 19:51 ` [RFC PATCH v7 18/23] entry/idle: Enter and exit kernel protection during idle entry and exit Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 19/23] entry/kvm: Protect the kernel when entering from guest Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 20/23] sched/coresched: config option for kernel protection Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 21/23] sched: cgroup tagging interface for core scheduling Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 22/23] Documentation: Add documentation on " Julien Desfossez
2020-08-28 19:51 ` [RFC PATCH v7 23/23] sched: Debug bits Julien Desfossez
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=9471f752-1a30-d46f-be75-d3d433980385@linux.microsoft.com \
--to=viremana@linux.microsoft.com \
--cc=aaron.lwe@gmail.com \
--cc=agata.gruza@intel.com \
--cc=antonio.gomez.iglesias@intel.com \
--cc=aubrey.intel@gmail.com \
--cc=aubrey.li@linux.intel.com \
--cc=benbjiang@tencent.com \
--cc=chris.hyser@oracle.com \
--cc=christian.brauner@ubuntu.com \
--cc=derkling@google.com \
--cc=dfaggioli@suse.com \
--cc=dhaval.giani@oracle.com \
--cc=fweisbec@gmail.com \
--cc=graf@amazon.com \
--cc=jdesfossez@digitalocean.com \
--cc=joel@joelfernandes.org \
--cc=keescook@chromium.org \
--cc=kerrnel@google.com \
--cc=konrad.wilk@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mingo@kernel.org \
--cc=naravamudan@digitalocean.com \
--cc=pauld@redhat.com \
--cc=paulmck@kernel.org \
--cc=pawan.kumar.gupta@linux.intel.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=pjt@google.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=tim.c.chen@intel.com \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
--cc=valentin.schneider@arm.com \
--cc=vineeth@bitbyteword.org \
--cc=yu.c.chen@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;
as well as URLs for NNTP newsgroup(s).