From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Alex Belits <abelits@marvell.com>,
"frederic\@kernel.org" <frederic@kernel.org>,
"rostedt\@goodmis.org" <rostedt@goodmis.org>,
Prasun Kapoor <pkapoor@marvell.com>,
"mingo\@kernel.org" <mingo@kernel.org>,
"davem\@davemloft.net" <davem@davemloft.net>,
"linux-api\@vger.kernel.org" <linux-api@vger.kernel.org>,
"linux-arch\@vger.kernel.org" <linux-arch@vger.kernel.org>,
"catalin.marinas\@arm.com" <catalin.marinas@arm.com>,
"will\@kernel.org" <will@kernel.org>,
"linux-arm-kernel\@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"netdev\@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v4 00/13] "Task_isolation" mode
Date: Thu, 23 Jul 2020 16:53:19 +0200 [thread overview]
Message-ID: <87y2nawae8.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20200723142623.GS5523@worktop.programming.kicks-ass.net>
Peter Zijlstra <peterz@infradead.org> writes:
> On Thu, Jul 23, 2020 at 03:17:04PM +0200, Thomas Gleixner wrote:
>
>> 2) Instruction synchronization
>>
>> Trying to do instruction synchronization delayed is a clear recipe
>> for hard to diagnose failures. Just because it blew not up in your
>> face does not make it correct in any way. It's broken by design and
>> violates _all_ rules of safe instruction patching and introduces a
>> complete trainwreck in x86 NMI processing.
>>
>> If you really think that this is correct, then please have at least
>> the courtesy to come up with a detailed and precise argumentation
>> why this is a valid approach.
>>
>> While writing that up you surely will find out why it is not.
>
> So delaying the sync_core() IPIs for kernel text patching _might_ be
> possible, but it very much wants to be a separate patchset and not
> something hidden inside a 'gem' like this.
I'm not saying it's impossible, but the proposed hack is definitely
beyond broken and you really don't want to be the one who has to mop up
the pieces later.
Thanks,
tglx
next prev parent reply other threads:[~2020-07-23 14:53 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-22 14:44 [PATCH v4 00/13] "Task_isolation" mode Alex Belits
2020-07-22 14:47 ` [PATCH v4 01/13] task_isolation: vmstat: add quiet_vmstat_sync function Alex Belits
2020-07-22 14:48 ` [PATCH v4 02/13] task_isolation: vmstat: add vmstat_idle function Alex Belits
2020-07-22 14:49 ` [PATCH v4 03/13] task_isolation: userspace hard isolation from kernel Alex Belits
2020-10-01 13:56 ` Frederic Weisbecker
2020-10-04 14:44 ` [EXT] " Alex Belits
2020-10-04 23:14 ` Frederic Weisbecker
2020-10-05 18:52 ` Nitesh Narayan Lal
2020-10-06 10:35 ` Frederic Weisbecker
2020-10-17 1:13 ` Alex Belits
2020-10-17 1:08 ` Alex Belits
2020-10-17 16:08 ` Thomas Gleixner
2020-10-17 16:15 ` Alex Belits
2020-10-17 20:03 ` Thomas Gleixner
2020-10-06 11:01 ` Alex Belits
2020-10-01 14:40 ` Frederic Weisbecker
2020-10-04 15:01 ` [EXT] " Alex Belits
2020-07-22 14:51 ` [PATCH v4 04/13] task_isolation: Add task isolation hooks to arch-independent code Alex Belits
2020-07-22 14:51 ` [PATCH v4 05/13] task_isolation: Add xen-specific hook Alex Belits
2020-07-22 14:53 ` [PATCH 06/13] task_isolation: Add driver-specific hooks Alex Belits
2020-07-22 14:54 ` [PATCH v4 07/13] task_isolation: arch/x86: enable task isolation functionality Alex Belits
2020-07-22 14:55 ` [PATCH 08/13] task_isolation: arch/arm64: " Alex Belits
2020-07-22 14:56 ` [PATCH v4 09/13] task_isolation: arch/arm: " Alex Belits
2020-07-22 14:57 ` [PATCH v4 10/13] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu() Alex Belits
2020-10-01 14:44 ` Frederic Weisbecker
2020-10-04 15:22 ` [EXT] " Alex Belits
2020-10-06 21:41 ` Frederic Weisbecker
2020-10-17 0:17 ` Alex Belits
2020-07-22 14:58 ` [PATCH v4 11/13] task_isolation: net: don't flush backlog on CPUs running isolated tasks Alex Belits
2020-10-01 14:47 ` Frederic Weisbecker
2020-10-04 17:12 ` [EXT] " Alex Belits
2021-01-22 14:13 ` Marcelo Tosatti
2021-01-22 16:13 ` Paolo Abeni
2020-07-22 14:59 ` [PATCH v4 12/13] task_isolation: ringbuffer: don't interrupt CPUs running isolated tasks on buffer resize Alex Belits
2020-07-22 14:59 ` [PATCH 13/13] task_isolation: kick_all_cpus_sync: don't kick isolated cpus Alex Belits
2020-07-23 13:17 ` [PATCH v4 00/13] "Task_isolation" mode Thomas Gleixner
2020-07-23 14:26 ` Peter Zijlstra
2020-07-23 14:53 ` Thomas Gleixner [this message]
2020-07-23 14:29 ` Peter Zijlstra
2020-07-23 15:41 ` [EXT] " Alex Belits
2020-07-23 15:48 ` Peter Zijlstra
2020-07-23 16:19 ` Alex Belits
2020-07-23 15:18 ` Alex Belits
2020-07-23 15:49 ` Peter Zijlstra
2020-07-23 16:50 ` Alex Belits
2020-07-23 21:44 ` Thomas Gleixner
2020-07-24 3:00 ` [EXT] " Alex Belits
2020-07-24 16:08 ` Thomas Gleixner
2020-07-23 21:31 ` Thomas Gleixner
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