From: Frederic Weisbecker <frederic@kernel.org>
To: Alex Belits <abelits@marvell.com>
Cc: "nitesh@redhat.com" <nitesh@redhat.com>,
Prasun Kapoor <pkapoor@marvell.com>,
"linux-api@vger.kernel.org" <linux-api@vger.kernel.org>,
"davem@davemloft.net" <davem@davemloft.net>,
"trix@redhat.com" <trix@redhat.com>,
"mingo@kernel.org" <mingo@kernel.org>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"peterx@redhat.com" <peterx@redhat.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"mtosatti@redhat.com" <mtosatti@redhat.com>,
"will@kernel.org" <will@kernel.org>,
"peterz@infradead.org" <peterz@infradead.org>,
"leon@sidebranch.com" <leon@sidebranch.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"pauld@redhat.com" <pauld@redhat.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v5 7/9] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu()
Date: Mon, 23 Nov 2020 23:13:36 +0100 [thread overview]
Message-ID: <20201123221336.GB1751@lothringen> (raw)
In-Reply-To: <76ed0b222d2f16fb5aebd144ac0222a7f3b87fa1.camel@marvell.com>
Hi Alex,
On Mon, Nov 23, 2020 at 05:58:22PM +0000, Alex Belits wrote:
> From: Yuri Norov <ynorov@marvell.com>
>
> For nohz_full CPUs the desirable behavior is to receive interrupts
> generated by tick_nohz_full_kick_cpu(). But for hard isolation it's
> obviously not desirable because it breaks isolation.
>
> This patch adds check for it.
>
> Signed-off-by: Yuri Norov <ynorov@marvell.com>
> [abelits@marvell.com: updated, only exclude CPUs running isolated tasks]
> Signed-off-by: Alex Belits <abelits@marvell.com>
> ---
> kernel/time/tick-sched.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> index a213952541db..6c8679e200f0 100644
> --- a/kernel/time/tick-sched.c
> +++ b/kernel/time/tick-sched.c
> @@ -20,6 +20,7 @@
> #include <linux/sched/clock.h>
> #include <linux/sched/stat.h>
> #include <linux/sched/nohz.h>
> +#include <linux/isolation.h>
> #include <linux/module.h>
> #include <linux/irq_work.h>
> #include <linux/posix-timers.h>
> @@ -268,7 +269,8 @@ static void tick_nohz_full_kick(void)
> */
> void tick_nohz_full_kick_cpu(int cpu)
> {
> - if (!tick_nohz_full_cpu(cpu))
> + smp_rmb();
> + if (!tick_nohz_full_cpu(cpu) || task_isolation_on_cpu(cpu))
> return;
Like I said in subsequent reviews, we are not going to ignore IPIs.
We must fix the sources of these IPIs instead.
Thanks.
>
> irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu);
> --
> 2.20.1
>
next prev parent reply other threads:[~2020-11-23 22:13 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-23 17:42 [PATCH v5 0/9] "Task_isolation" mode Alex Belits
2020-11-23 17:56 ` [PATCH v5 1/9] task_isolation: vmstat: add quiet_vmstat_sync function Alex Belits
2020-11-23 21:48 ` Thomas Gleixner
2020-11-23 17:56 ` [PATCH v5 2/9] task_isolation: vmstat: add vmstat_idle function Alex Belits
2020-11-23 21:49 ` Thomas Gleixner
2020-11-23 17:56 ` [PATCH v5 3/9] task_isolation: userspace hard isolation from kernel Alex Belits
2020-11-23 22:01 ` Thomas Gleixner
2020-11-23 17:57 ` [PATCH v5 4/9] task_isolation: Add task isolation hooks to arch-independent code Alex Belits
2020-11-23 22:31 ` Thomas Gleixner
2020-11-23 17:57 ` [PATCH v5 5/9] task_isolation: Add driver-specific hooks Alex Belits
2020-12-02 14:18 ` Mark Rutland
2020-12-04 0:43 ` [EXT] " Alex Belits
2020-11-23 17:58 ` [PATCH v5 6/9] task_isolation: arch/arm64: enable task isolation functionality Alex Belits
2020-12-02 13:59 ` Mark Rutland
2020-12-04 0:37 ` [EXT] " Alex Belits
2020-12-07 11:57 ` Mark Rutland
2020-11-23 17:58 ` [PATCH v5 7/9] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu() Alex Belits
2020-11-23 22:13 ` Frederic Weisbecker [this message]
2020-11-23 22:35 ` Alex Belits
2020-11-23 22:36 ` Thomas Gleixner
2020-12-02 14:20 ` Mark Rutland
2020-12-04 0:54 ` [EXT] " Alex Belits
2020-12-07 11:58 ` Mark Rutland
2020-11-23 17:58 ` [PATCH v5 8/9] task_isolation: ringbuffer: don't interrupt CPUs running isolated tasks on buffer resize Alex Belits
2020-11-23 17:58 ` [PATCH v5 9/9] task_isolation: kick_all_cpus_sync: don't kick isolated cpus Alex Belits
2020-11-23 22:29 ` Frederic Weisbecker
2020-11-23 22:39 ` [EXT] " Alex Belits
2020-11-23 23:21 ` Frederic Weisbecker
2020-11-25 3:20 ` Alex Belits
2021-01-22 15:00 ` Marcelo Tosatti
2020-11-24 16:36 ` [PATCH v5 0/9] "Task_isolation" mode Tom Rix
2020-11-24 17:40 ` [EXT] " Alex Belits
2020-12-02 14:02 ` Mark Rutland
2020-12-04 0:39 ` Alex Belits
2020-12-05 20:40 ` Pavel Machek
2020-12-05 23:25 ` Thomas Gleixner
2020-12-11 18:08 ` Yury Norov
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