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From: Will Deacon <will@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
	Marc Zyngier <maz@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Morten Rasmussen <morten.rasmussen@arm.com>,
	Qais Yousef <qais.yousef@arm.com>,
	Suren Baghdasaryan <surenb@google.com>,
	kernel-team@android.com
Subject: Re: [PATCH 4/6] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs
Date: Wed, 28 Oct 2020 12:36:20 +0000	[thread overview]
Message-ID: <20201028123619.GB28091@willie-the-truck> (raw)
In-Reply-To: <20201028121052.GF13345@gaia>

On Wed, Oct 28, 2020 at 12:10:53PM +0000, Catalin Marinas wrote:
> On Tue, Oct 27, 2020 at 09:51:16PM +0000, Will Deacon wrote:
> > diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> > index 4784011cecac..c45b5f9dd66b 100644
> > --- a/arch/arm64/kernel/process.c
> > +++ b/arch/arm64/kernel/process.c
> > @@ -542,6 +542,17 @@ static void erratum_1418040_thread_switch(struct task_struct *prev,
> >  	write_sysreg(val, cntkctl_el1);
> >  }
> >  
> > +static void compat_thread_switch(struct task_struct *next)
> > +{
> > +	if (!is_compat_thread(task_thread_info(next)))
> > +		return;
> > +
> > +	if (!system_has_mismatched_32bit_el0())
> > +		return;
> > +
> > +	set_tsk_thread_flag(next, TIF_NOTIFY_RESUME);
> > +}
> 
> I wonder whether you could use set_notify_resume() for consistency.

I looked at that, but it ends up kicking the task which is not needed
here and can result in a reschedule via preempt_enable().

Will

  reply	other threads:[~2020-10-28 22:19 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-27 21:51 [PATCH 0/6] An alternative series for asymmetric AArch32 systems Will Deacon
2020-10-27 21:51 ` [PATCH 1/6] KVM: arm64: Handle Asymmetric " Will Deacon
2020-10-27 21:51 ` [PATCH 2/6] arm64: Allow mismatched 32-bit EL0 support Will Deacon
2020-10-28 11:12   ` Catalin Marinas
2020-10-28 11:17     ` Will Deacon
2020-10-28 11:22       ` Catalin Marinas
2020-10-28 11:23         ` Will Deacon
2020-10-28 11:49           ` Catalin Marinas
2020-10-28 12:40             ` Will Deacon
2020-10-28 18:56               ` Catalin Marinas
2020-10-29 22:20                 ` Will Deacon
2020-10-30 11:18                   ` Catalin Marinas
2020-10-30 16:13                     ` Will Deacon
2020-11-02 11:44                       ` Catalin Marinas
2020-11-05 21:38                         ` Will Deacon
2020-11-06 12:54                           ` Qais Yousef
2020-11-06 13:00                             ` Will Deacon
2020-11-06 14:48                               ` Qais Yousef
2020-11-09 13:52                                 ` Will Deacon
2020-11-11 16:27                                   ` Qais Yousef
2020-11-12 10:24                                     ` Will Deacon
2020-11-12 11:55                                       ` Qais Yousef
2020-11-12 16:49                                         ` Qais Yousef
2020-11-12 17:06                                           ` Marc Zyngier
2020-11-12 17:36                                             ` Qais Yousef
2020-11-12 17:44                                               ` Will Deacon
2020-11-12 17:36                                           ` Will Deacon
2020-11-13 10:45                                             ` Qais Yousef
2020-11-06 14:30                           ` Catalin Marinas
2020-10-28 11:18   ` Catalin Marinas
2020-10-28 11:21     ` Will Deacon
2020-10-27 21:51 ` [PATCH 3/6] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon
2020-10-27 21:51 ` [PATCH 4/6] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon
2020-10-28 12:10   ` Catalin Marinas
2020-10-28 12:36     ` Will Deacon [this message]
2020-10-27 21:51 ` [PATCH 5/6] arm64: Advertise CPUs capable of running 32-bit applcations in sysfs Will Deacon
2020-10-28  8:37   ` Greg Kroah-Hartman
2020-10-28  9:51     ` Will Deacon
2020-10-28 12:15   ` Catalin Marinas
2020-10-28 12:27     ` Will Deacon
2020-10-28 15:14       ` Catalin Marinas
2020-10-28 15:35         ` Will Deacon
2020-10-27 21:51 ` [PATCH 6/6] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon
2020-10-29 18:42 ` [PATCH 0/6] An alternative series for asymmetric AArch32 systems Suren Baghdasaryan
2020-10-29 22:17   ` Will Deacon
2020-10-30 16:16 ` Marc Zyngier
2020-10-30 16:24   ` Will Deacon
2020-10-30 17:04     ` Marc Zyngier

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