From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>,
Stefan Hajnoczi <stefanha@redhat.com>,
Jason Wang <jasowang@redhat.com>,
"x86@kernel.org" <x86@kernel.org>, hpa <hpa@zytor.com>,
dyoung <dyoung@redhat.com>, kexec <kexec@lists.infradead.org>,
linux-ext4 <linux-ext4@vger.kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Stefano Garzarella <sgarzare@redhat.com>,
eperezma <eperezma@redhat.com>,
Paolo Bonzini <bonzini@redhat.com>,
ming.lei@redhat.com, Petr Mladek <pmladek@suse.com>,
John Ogness <jogness@linutronix.de>
Subject: Re: Lockdep warnings on kexec (virtio_blk, hrtimers)
Date: Fri, 13 Dec 2024 12:20:28 +0100 [thread overview]
Message-ID: <20241213112028.GE21636@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <874j38a16p.ffs@tglx>
On Fri, Dec 13, 2024 at 01:14:54AM +0100, Thomas Gleixner wrote:
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -7276,7 +7276,7 @@ void rt_mutex_setprio(struct task_struct
> #if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC)
> int __sched __cond_resched(void)
> {
> - if (should_resched(0)) {
> + if (should_resched(0) && system_state != SYSTEM_SUSPEND) {
> preempt_schedule_common();
> return 1;
> }
Perhaps we should just do:
if (should_resched(0) && !irqs_disabled())
That's more or less what preemptible() does too. Yes, mucking about with
IF is expensive, but it's only done if preempt_count is agreeing we
should schedule, which it shouldn't be most of the time.
next prev parent reply other threads:[~2024-12-13 11:21 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-09 14:28 Lockdep warnings on kexec (virtio_blk, hrtimers) David Woodhouse
2024-12-10 1:56 ` Jason Wang
2024-12-11 12:42 ` Stefan Hajnoczi
2024-12-12 11:07 ` David Woodhouse
2024-12-12 13:34 ` Thomas Gleixner
2024-12-12 13:46 ` David Woodhouse
2024-12-12 18:04 ` Thomas Gleixner
2024-12-12 19:19 ` David Woodhouse
2024-12-13 0:14 ` Thomas Gleixner
2024-12-13 9:31 ` David Woodhouse
2024-12-13 9:43 ` David Woodhouse
2024-12-13 10:42 ` Thomas Gleixner
2024-12-13 11:09 ` Ming Lei
2024-12-13 11:31 ` Thomas Gleixner
2024-12-13 11:48 ` Ming Lei
2024-12-13 13:23 ` Thomas Gleixner
2024-12-13 14:07 ` David Woodhouse
2024-12-13 17:05 ` Thomas Gleixner
2024-12-13 17:17 ` David Woodhouse
2024-12-13 17:48 ` Rafael J. Wysocki
2024-12-13 17:32 ` Rafael J. Wysocki
2024-12-13 19:06 ` Rafael J. Wysocki
2024-12-13 20:16 ` David Woodhouse
2024-12-14 9:57 ` David Woodhouse
2024-12-16 12:14 ` Rafael J. Wysocki
2024-12-13 17:59 ` Rafael J. Wysocki
2024-12-13 13:17 ` David Woodhouse
2024-12-13 11:12 ` David Woodhouse
2024-12-13 11:33 ` Ming Lei
2024-12-13 11:20 ` Peter Zijlstra [this message]
2024-12-13 13:13 ` Thomas Gleixner
2024-12-16 13:20 ` [PATCH] sched: Prevent rescheduling when interrupts are disabled Thomas Gleixner
2024-12-16 17:41 ` David Woodhouse
2024-12-12 11:12 ` Lockdep warnings on kexec (virtio_blk, hrtimers) Ming Lei
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