From: Paul Mundt <lethal@linux-sh.org>
To: Stephen Boyd <sboyd@codeaurora.org>
Cc: Russell King <linux@arm.linux.org.uk>,
linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-omap@vger.kernel.org,
linux-sh@vger.kernel.org, linux-tegra@vger.kernel.org,
Kukjin Kim <kgene.kim@samsung.com>,
David Brown <davidb@codeaurora.org>,
Tony Lindgren <tony@atomide.com>,
Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>,
Linus Walleij <linus.walleij@stericsson.com>
Subject: Re: [PATCH] arm: platsmp: Allow secondary cpu hotplug with maxcpus=1
Date: Thu, 30 Jun 2011 14:38:52 +0900 [thread overview]
Message-ID: <20110630053851.GC22023@linux-sh.org> (raw)
In-Reply-To: <1309372300-28911-1-git-send-email-sboyd@codeaurora.org>
On Wed, Jun 29, 2011 at 11:31:39AM -0700, Stephen Boyd wrote:
> If an ARM system has multiple cpus in the same socket and the
> kernel is booted with maxcpus=1, secondary cpus are possible but
> not present due to how platform_smp_prepare_cpus() is called.
> Fix this by always calling platform_smp_prepare_cpus() as long as
> max_cpus is non-zero (0 means no SMP) to allow platform code to
> decide if any non-boot cpus are present in the system. Since
> all current platform code doesn't support physical hotplug we
> have a situation where possible == present and thus we can
> simply copy the possible map to the present map.
>
> With this patch it's possible to boot an ARM system with
> maxcpus=1 on the command line and then hotplug in secondary cpus
> via sysfs. This is more in line with how x86 works with maxcpus=1
> on the command line.
>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
WARNING: multiple messages have this Message-ID (diff)
From: Paul Mundt <lethal@linux-sh.org>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm: platsmp: Allow secondary cpu hotplug with maxcpus=1
Date: Thu, 30 Jun 2011 05:38:52 +0000 [thread overview]
Message-ID: <20110630053851.GC22023@linux-sh.org> (raw)
In-Reply-To: <1309372300-28911-1-git-send-email-sboyd@codeaurora.org>
On Wed, Jun 29, 2011 at 11:31:39AM -0700, Stephen Boyd wrote:
> If an ARM system has multiple cpus in the same socket and the
> kernel is booted with maxcpus=1, secondary cpus are possible but
> not present due to how platform_smp_prepare_cpus() is called.
> Fix this by always calling platform_smp_prepare_cpus() as long as
> max_cpus is non-zero (0 means no SMP) to allow platform code to
> decide if any non-boot cpus are present in the system. Since
> all current platform code doesn't support physical hotplug we
> have a situation where possible = present and thus we can
> simply copy the possible map to the present map.
>
> With this patch it's possible to boot an ARM system with
> maxcpus=1 on the command line and then hotplug in secondary cpus
> via sysfs. This is more in line with how x86 works with maxcpus=1
> on the command line.
>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
WARNING: multiple messages have this Message-ID (diff)
From: lethal@linux-sh.org (Paul Mundt)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm: platsmp: Allow secondary cpu hotplug with maxcpus=1
Date: Thu, 30 Jun 2011 14:38:52 +0900 [thread overview]
Message-ID: <20110630053851.GC22023@linux-sh.org> (raw)
In-Reply-To: <1309372300-28911-1-git-send-email-sboyd@codeaurora.org>
On Wed, Jun 29, 2011 at 11:31:39AM -0700, Stephen Boyd wrote:
> If an ARM system has multiple cpus in the same socket and the
> kernel is booted with maxcpus=1, secondary cpus are possible but
> not present due to how platform_smp_prepare_cpus() is called.
> Fix this by always calling platform_smp_prepare_cpus() as long as
> max_cpus is non-zero (0 means no SMP) to allow platform code to
> decide if any non-boot cpus are present in the system. Since
> all current platform code doesn't support physical hotplug we
> have a situation where possible == present and thus we can
> simply copy the possible map to the present map.
>
> With this patch it's possible to boot an ARM system with
> maxcpus=1 on the command line and then hotplug in secondary cpus
> via sysfs. This is more in line with how x86 works with maxcpus=1
> on the command line.
>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
next prev parent reply other threads:[~2011-06-30 5:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-29 18:31 [PATCH] arm: platsmp: Allow secondary cpu hotplug with maxcpus=1 Stephen Boyd
2011-06-29 18:31 ` Stephen Boyd
2011-06-29 18:31 ` Stephen Boyd
2011-06-30 5:38 ` Paul Mundt [this message]
2011-06-30 5:38 ` Paul Mundt
2011-06-30 5:38 ` Paul Mundt
2011-06-30 13:11 ` Russell King - ARM Linux
2011-06-30 13:11 ` Russell King - ARM Linux
2011-06-30 13:11 ` [PATCH] arm: platsmp: Allow secondary cpu hotplug with Russell King - ARM Linux
2011-06-30 16:36 ` [PATCH] arm: platsmp: Allow secondary cpu hotplug with maxcpus=1 Stephen Boyd
2011-06-30 16:36 ` Stephen Boyd
2011-06-30 16:36 ` Stephen Boyd
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110630053851.GC22023@linux-sh.org \
--to=lethal@linux-sh.org \
--cc=davidb@codeaurora.org \
--cc=kgene.kim@samsung.com \
--cc=linus.walleij@stericsson.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=linux-sh@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=sboyd@codeaurora.org \
--cc=srinidhi.kasagar@stericsson.com \
--cc=tony@atomide.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.