From: Arnd Bergmann <arnd@arndb.de>
To: "long.wanglong" <long.wanglong@huawei.com>
Cc: linux@arm.linux.org.uk, santosh.shilimkar@ti.com,
victor.kamensky@linaro.org, nico@linaro.org,
ben.dooks@codethink.co.uk, cov@codeaurora.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [SMP BUG?] the return value of is_smp() is bug?
Date: Mon, 01 Sep 2014 12:26 +0200 [thread overview]
Message-ID: <25226905.0IHWyHSRxb@wuerfel> (raw)
In-Reply-To: <540443DA.7030502@huawei.com>
On Monday 01 September 2014 18:00:58 long.wanglong wrote:
> On 2014/9/1 13:49, Wang Long wrote:
> >
> > Hi,all
> >
> > In kernel 3.17-rc2, when i set CONFIG_HAVE_SMP = y and CONFIG_SMP_ON_UP = y
> > in .config file. the secondary core can not boot.
> >
> > when i set CONFIG_HAVE_SMP = y and CONFIG_SMP_ON_UP = n in .config file,
> > the secondary core can boot.
> >
> > But this does not happen in kernel 3.10 lts kernel, Whether the
> > CONFIG_SMP_ON_UP is set yes or no ,the secondary core can boot.
> >
> > Does the meaning of CONFIG_SMP_ON_UP changed or this is a bug in kernel 3.17-rc2 ?
> >
> >
>
> hi Arnd
>
> In above two cases, i also set CONFIG_SMP = y. in addtion,
> the CONFIG_SMP_ON_UP depends on CONFIG_SMP. when set
> CONFIG_SMP_ON_UP = y, the value of CONFIG_SMP must be y.
I see.
I'm looking at the code more closely now:
> > config: set CONFIG_HAVE_SMP = y and CONFIG_SMP_ON_UP = y
> > command: # qemu-system-arm -M vexpress-a9 -smp 2 -m 128M -kernel arch/arm/boot/zImage -nographic
> > The output:
> >
> > ..........
> > is_smp() return false;
This test basically checks whether the __fixup_smp_on_up code was
run or not. This has changed in bc41b8724f24 "ARM: 7846/1: Update
SMP_ON_UP code to detect A9MPCore with 1 CPU devices", in order
to support a quirk in the Aegis platform. Can you try reverting
that commit?
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [SMP BUG?] the return value of is_smp() is bug?
Date: Mon, 01 Sep 2014 12:26 +0200 [thread overview]
Message-ID: <25226905.0IHWyHSRxb@wuerfel> (raw)
In-Reply-To: <540443DA.7030502@huawei.com>
On Monday 01 September 2014 18:00:58 long.wanglong wrote:
> On 2014/9/1 13:49, Wang Long wrote:
> >
> > Hi,all
> >
> > In kernel 3.17-rc2, when i set CONFIG_HAVE_SMP = y and CONFIG_SMP_ON_UP = y
> > in .config file. the secondary core can not boot.
> >
> > when i set CONFIG_HAVE_SMP = y and CONFIG_SMP_ON_UP = n in .config file,
> > the secondary core can boot.
> >
> > But this does not happen in kernel 3.10 lts kernel, Whether the
> > CONFIG_SMP_ON_UP is set yes or no ,the secondary core can boot.
> >
> > Does the meaning of CONFIG_SMP_ON_UP changed or this is a bug in kernel 3.17-rc2 ?
> >
> >
>
> hi Arnd
>
> In above two cases, i also set CONFIG_SMP = y. in addtion,
> the CONFIG_SMP_ON_UP depends on CONFIG_SMP. when set
> CONFIG_SMP_ON_UP = y, the value of CONFIG_SMP must be y.
I see.
I'm looking at the code more closely now:
> > config: set CONFIG_HAVE_SMP = y and CONFIG_SMP_ON_UP = y
> > command: # qemu-system-arm -M vexpress-a9 -smp 2 -m 128M -kernel arch/arm/boot/zImage -nographic
> > The output:
> >
> > ..........
> > is_smp() return false;
This test basically checks whether the __fixup_smp_on_up code was
run or not. This has changed in bc41b8724f24 "ARM: 7846/1: Update
SMP_ON_UP code to detect A9MPCore with 1 CPU devices", in order
to support a quirk in the Aegis platform. Can you try reverting
that commit?
Arnd
next prev parent reply other threads:[~2014-09-01 10:26 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-01 5:49 [SMP BUG?] the return value of is_smp() is bug? Wang Long
2014-09-01 5:49 ` Wang Long
2014-09-01 10:00 ` long.wanglong
2014-09-01 10:00 ` long.wanglong
2014-09-01 10:26 ` Arnd Bergmann [this message]
2014-09-01 10:26 ` Arnd Bergmann
2014-09-04 1:13 ` long.wanglong
2014-09-04 1:13 ` long.wanglong
2014-09-04 8:33 ` Peter Maydell
2014-09-04 8:33 ` Peter Maydell
2014-09-01 11:15 Wang Long
2014-09-01 11:15 ` Wang Long
2014-09-02 4:40 ` Leon Yu
2014-09-01 11:35 Wang Long
2014-09-01 11:35 ` Wang Long
2014-09-01 8:49 ` Arnd Bergmann
2014-09-01 8:49 ` Arnd Bergmann
2014-09-01 10:19 ` Russell King - ARM Linux
2014-09-01 10:19 ` Russell King - ARM Linux
2014-09-04 1:01 ` long.wanglong
2014-09-04 1:01 ` long.wanglong
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