From: Arjan van de Ven <arjan@infradead.org>
To: "Youquan,Song" <youquan.song@linux.intel.com>
Cc: hpa@zytor.com, tglx@linutronix.de, akpm@linux-foundation.org,
venkatesh.pallipadi@intel.com, suresh.b.siddha@intel.com,
kent.liu@intel.com, chaohong.guo@intel.com,
youquan.song@intel.com, linux-acpi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH]tickless: Fix tick nohz timer irq0 fail to increaase
Date: Mon, 4 Jan 2010 04:36:50 -0800 [thread overview]
Message-ID: <20100104043650.6acfb056@infradead.org> (raw)
In-Reply-To: <20100104104905.GA30574@youquan-linux.bj.intel.com>
On Mon, 4 Jan 2010 05:49:05 -0500
"Youquan,Song" <youquan.song@linux.intel.com> wrote:
> Tickless is disabled by nohz=off, which is used in OSVs.
it is? I doubt anyone wants to normally disable tickless, the power
cost is just too high....
> But in
> current kernel, if tickless is disabled, the timer irq0 will not
> increase.
why is this a problem?
> Because the timer event handler should be
> tick_handle_periodic, but actually event handler keep as
> tick_handle_oneshot_broadcast which is used in tickless. The root
> cause is that it is default to enable high resolution timer which
> will force to oneshot broadcast mode.
using local apic in one shot mode is not a problem, I'd in fact call it
a feature...
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2010-01-04 12:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20091214130233.GA3898@youquan-linux.bj.intel.com>
2010-01-04 10:49 ` Youquan,Song
2010-01-04 12:36 ` Arjan van de Ven [this message]
2010-01-04 14:00 ` Peter Zijlstra
2010-01-04 22:02 ` Youquan,Song
2010-01-04 21:40 ` Youquan,Song
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=20100104043650.6acfb056@infradead.org \
--to=arjan@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=chaohong.guo@intel.com \
--cc=hpa@zytor.com \
--cc=kent.liu@intel.com \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=suresh.b.siddha@intel.com \
--cc=tglx@linutronix.de \
--cc=venkatesh.pallipadi@intel.com \
--cc=youquan.song@intel.com \
--cc=youquan.song@linux.intel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome