From: Jan Kiszka <jan.kiszka@siemens.com>
To: Thomas Gleixner <tglx@linutronix.de>, Avi Kivity <avi@redhat.com>
Cc: KVM <kvm@vger.kernel.org>, Gleb Natapov <gleb@redhat.com>,
RT <linux-rt-users@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [patch] x86: kvm: Convert i8254/i8259 locks to raw_spinlocks
Date: Tue, 23 Feb 2010 20:18:55 +0100 [thread overview]
Message-ID: <4B842A1F.50601@siemens.com> (raw)
In-Reply-To: <20100217135901.331576359@linutronix.de>
Thomas Gleixner wrote:
> The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert
> them to raw_spinlock. No change for !RT kernels.
Doesn't fly for -rt anymore: pic_irq_update runs under this raw lock and
calls kvm_vcpu_kick which tries to wake_up some thread -> scheduling
while atomic.
This used to work up to 956f97cf. -rt for 2.6.31 is not yet affected,
but 2.6.33 should be broken (haven't checked, using kvm-kmod over 2.6.31
ATM). I can provide a patch that restores the deferred kicking if it's
acceptable for upstream.
Jan
--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2010-02-23 19:18 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-17 14:00 [patch] x86: kvm: Convert i8254/i8259 locks to raw_spinlocks Thomas Gleixner
2010-02-18 9:12 ` Jan Kiszka
2010-02-18 9:20 ` Avi Kivity
2010-02-18 9:40 ` Jan Kiszka
2010-02-18 9:45 ` Avi Kivity
2010-02-18 9:49 ` Jan Kiszka
2010-02-18 9:53 ` Avi Kivity
2010-02-18 9:50 ` Avi Kivity
2010-02-18 10:05 ` Jan Kiszka
2010-02-18 10:18 ` Avi Kivity
2010-02-19 1:14 ` Marcelo Tosatti
2010-02-18 9:19 ` Avi Kivity
2010-02-23 19:18 ` Jan Kiszka [this message]
2010-02-23 22:23 ` Thomas Gleixner
2010-02-24 9:41 ` [PATCH] KVM: x86: Kick VCPU outside PIC lock again Jan Kiszka
2010-02-24 9:48 ` Avi Kivity
2010-02-24 9:54 ` Jan Kiszka
2010-02-24 10:04 ` Avi Kivity
2010-02-24 10:13 ` Jan Kiszka
2010-02-24 10:17 ` Avi Kivity
2010-02-24 10:22 ` Jan Kiszka
2010-02-24 10:27 ` Avi Kivity
2010-02-24 10:31 ` Jan Kiszka
2010-02-24 10:28 ` Jan Kiszka
2010-02-24 10:41 ` Avi Kivity
2010-02-24 11:42 ` Jan Kiszka
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