From: Srivatsa Vaddagiri <vatsa@in.ibm.com>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@osdl.org>, Dave Jones <davej@redhat.com>,
Ingo Molnar <mingo@elte.hu>,
Chuck Ebbert <76306.1226@compuserve.com>,
Ashok Raj <ashok.raj@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>
Subject: Re: [patch] Reorganize the cpufreq cpu hotplug locking to not be totally bizare
Date: Wed, 26 Jul 2006 14:21:02 -0700 [thread overview]
Message-ID: <20060726212102.GA23787@in.ibm.com> (raw)
In-Reply-To: <1153947786.3381.58.camel@laptopd505.fenrus.org>
On Wed, Jul 26, 2006 at 11:03:06PM +0200, Arjan van de Ven wrote:
> rwsems unfortunately help you zilch; an rwsem is just a mutex with a
> performance tweak, but from the deadlock perspective it's really a
> mutex.
ah ..didnt realize that.
> I'm really starting to feel that the hotplug lock would have been better
> of being a refcount (with a waitqueue for zero) than a lock. While
> "refcount+waitqueue" sort of IS a lock, the semantics make more sense
> imo...
I think that will work, although you now need to deal with a global or per-cpu
refcount now. Later is more cache-friendly, but dont think we have ready
refcounting APIs for that?
--
Regards,
vatsa
next prev parent reply other threads:[~2006-07-26 21:29 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-25 0:21 remove cpu hotplug bustification in cpufreq Chuck Ebbert
2006-07-25 0:59 ` Linus Torvalds
2006-07-25 15:06 ` Erik Mouw
2006-07-25 18:54 ` Ingo Molnar
2006-07-25 19:30 ` Arjan van de Ven
2006-07-25 20:57 ` Linus Torvalds
2006-07-26 13:40 ` [patch] Reorganize the cpufreq cpu hotplug locking to not be totally bizare Arjan van de Ven
2006-07-26 15:51 ` Dave Jones
2006-07-26 17:09 ` Linus Torvalds
2006-07-26 19:42 ` Arjan van de Ven
2006-07-26 20:22 ` Linus Torvalds
2006-07-26 20:58 ` Srivatsa Vaddagiri
2006-07-26 21:29 ` Linus Torvalds
2006-07-26 21:38 ` Arjan van de Ven
2006-07-27 1:40 ` Ingo Molnar
2006-07-27 17:38 ` Ashok Raj
2006-07-29 13:45 ` Ingo Molnar
2006-07-26 21:15 ` Ashok Raj
2006-07-27 19:29 ` Langsdorf, Mark
2006-07-28 13:50 ` Andi Kleen
2006-07-28 17:09 ` Langsdorf, Mark
2006-07-26 20:42 ` Srivatsa Vaddagiri
2006-07-26 21:03 ` Arjan van de Ven
2006-07-26 21:21 ` Srivatsa Vaddagiri [this message]
2006-07-26 21:33 ` Rafael J. Wysocki
2006-07-26 21:33 ` Andrew Morton
2006-07-26 22:35 ` Sanjoy Mahajan
2006-07-26 22:44 ` Arjan van de Ven
2006-07-25 20:46 ` remove cpu hotplug bustification in cpufreq Dave Jones
2006-07-25 20:59 ` Linus Torvalds
2006-07-26 17:12 ` Russell King
2006-07-26 17:53 ` Dave Jones
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=20060726212102.GA23787@in.ibm.com \
--to=vatsa@in.ibm.com \
--cc=76306.1226@compuserve.com \
--cc=akpm@osdl.org \
--cc=arjan@linux.intel.com \
--cc=ashok.raj@intel.com \
--cc=davej@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=torvalds@osdl.org \
/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.