From: Oleg Nesterov <oleg@tv-sign.ru>
To: Gautham R Shenoy <ego@in.ibm.com>
Cc: Christoph Lameter <clameter@sgi.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org,
Rusty Russel <rusty@rustcorp.com.au>,
Srivatsa Vaddagiri <vatsa@in.ibm.com>,
Dipankar Sarma <dipankar@in.ibm.com>, Ingo Molnar <mingo@elte.hu>,
Paul E McKenney <paulmck@us.ibm.com>,
Richard Gooch <rgooch@atnf.csiro.au>,
Tigran Aivazian <tigran@aivazian.fs.co.uk>,
Shoahua Li <shaohua.li@linux.com>,
Ralf Baechle <ralf@linux-mips.org>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Nathan Lynch <ntl@pobox.com>, David Miller <davem@davemloft.net>,
Paul Jackson <pj@sgi.com>, Josh Triplett <josh@freedesktop.org>,
Pekka Enberg <penberg@cs.helsinki.fi>,
Akinobu Mita <akinobu.mita@gmail.com>
Subject: Re: [RFC PATCH 0/5] Refcount based Cpu Hotplug. V2
Date: Wed, 24 Oct 2007 22:17:54 +0400 [thread overview]
Message-ID: <20071024181754.GC345@tv-sign.ru> (raw)
In-Reply-To: <20071024180034.GB8663@in.ibm.com>
On 10/24, Gautham R Shenoy wrote:
>
> On Wed, Oct 24, 2007 at 10:04:41AM -0700, Christoph Lameter wrote:
> > On Wed, 24 Oct 2007, Gautham R Shenoy wrote:
> >
> > > This is the version 2 of the refcount based cpu-hotplug "locking"
> > > implementation.
> >
> > Uggh. This introduces a global lock that has to be taken always when
> > scanning over cpus?
>
> Well, no! we take the global lock only while bumping up the refcount.
> We don't hold the lock while scanning over the cpus. And this is
> definitely an improvement over the lock_cpu_hotplug() global mutex
> we have now.
Just to be sure I didn't miss something... preempt_disable() still works,
yes?
Oleg.
next prev parent reply other threads:[~2007-10-24 18:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-24 5:29 [RFC PATCH 0/5] Refcount based Cpu Hotplug. V2 Gautham R Shenoy
2007-10-24 5:30 ` [RFC PATCH 1/5] Refcount Based Cpu Hotplug implementation Gautham R Shenoy
2007-10-24 5:32 ` [RFC PATCH 2/5] Replace lock_cpu_hotplug() with get_online_cpus() Gautham R Shenoy
2007-10-24 5:34 ` [RFC PATCH 3/5] Replace per-subsystem mutexes " Gautham R Shenoy
2007-10-24 5:37 ` [RFC PATCH 4/5] Remove CPU_DEAD/CPU_UP_CANCELLED handling from workqueue.c Gautham R Shenoy
2007-10-24 7:21 ` Rusty Russell
2007-10-24 8:35 ` Gautham R Shenoy
2007-10-24 13:44 ` Oleg Nesterov
2007-10-24 13:38 ` Oleg Nesterov
2007-10-24 17:45 ` Gautham R Shenoy
2007-10-24 18:14 ` Oleg Nesterov
2007-10-24 5:39 ` [RFC PATCH 5/5] Update get_online_cpus() in Documentation/cpu-hotplug.c Gautham R Shenoy
2007-10-24 17:04 ` [RFC PATCH 0/5] Refcount based Cpu Hotplug. V2 Christoph Lameter
2007-10-24 18:00 ` Gautham R Shenoy
2007-10-24 18:17 ` Oleg Nesterov [this message]
2007-10-24 18:22 ` Gautham R Shenoy
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=20071024181754.GC345@tv-sign.ru \
--to=oleg@tv-sign.ru \
--cc=akinobu.mita@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=clameter@sgi.com \
--cc=davem@davemloft.net \
--cc=dipankar@in.ibm.com \
--cc=ego@in.ibm.com \
--cc=heiko.carstens@de.ibm.com \
--cc=josh@freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=ntl@pobox.com \
--cc=paulmck@us.ibm.com \
--cc=penberg@cs.helsinki.fi \
--cc=pj@sgi.com \
--cc=ralf@linux-mips.org \
--cc=rgooch@atnf.csiro.au \
--cc=rusty@rustcorp.com.au \
--cc=shaohua.li@linux.com \
--cc=tigran@aivazian.fs.co.uk \
--cc=torvalds@linux-foundation.org \
--cc=vatsa@in.ibm.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.