From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
tj@kernel.org, tglx@linutronix.de, peterz@infradead.org,
paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au,
mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org,
vincent.guittot@linaro.org, sbw@mit.edu,
amit.kucheria@linaro.org, rjw@sisk.pl,
wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com,
nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v2 01/10] CPU hotplug: Provide APIs for "light" atomic readers to prevent CPU offline
Date: Fri, 07 Dec 2012 23:03:14 +0530 [thread overview]
Message-ID: <50C2285A.60806@linux.vnet.ibm.com> (raw)
In-Reply-To: <1354831350.17101.31.camel@gandalf.local.home>
On 12/07/2012 03:32 AM, Steven Rostedt wrote:
> On Fri, 2012-12-07 at 01:06 +0530, Srivatsa S. Bhat wrote:
>> The root-cause of this deadlock is again lock-ordering mismatch right?
>> CPU0 takes locks in order A, B
>> CPU1 takes locks in order B, A
>>
>> And the writer facilitates in actually getting deadlocked.
>>
>> I avoid this in this patchset by always taking the locks in the same
>> order. So we won't be deadlocking like this.
>
> OK, I haven't looked closely at the patch yet. I'm currently hacking on
> my own problems. But just from the description above, it looked like you
> were using rw_locks() to be able to inverse the order of the locks.
>
Ah, ok, no problem! I'd be grateful if you could take a look when you
are free :-) I'll post a v3 soon, which has a completely redesigned
synchronization scheme, to address the performance concerns related to
global rwlocks that Tejun raised.
Regards,
Srivatsa S. Bhat
next prev parent reply other threads:[~2012-12-07 17:34 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-05 18:42 [RFC PATCH v2 00/10][RESEND] CPU hotplug: stop_machine()-free CPU hotplug Srivatsa S. Bhat
2012-12-05 18:43 ` [RFC PATCH v2 01/10] CPU hotplug: Provide APIs for "light" atomic readers to prevent CPU offline Srivatsa S. Bhat
2012-12-05 18:47 ` Srivatsa S. Bhat
2012-12-05 18:51 ` Srivatsa S. Bhat
2012-12-05 18:53 ` Srivatsa S. Bhat
2012-12-05 18:56 ` Srivatsa S. Bhat
2012-12-05 18:59 ` Srivatsa S. Bhat
2012-12-05 20:14 ` Srivatsa S. Bhat
2012-12-06 16:18 ` Oleg Nesterov
2012-12-06 18:48 ` Srivatsa S. Bhat
2012-12-06 19:17 ` Srivatsa S. Bhat
2012-12-07 21:01 ` Oleg Nesterov
2012-12-06 19:28 ` Steven Rostedt
2012-12-06 19:36 ` Srivatsa S. Bhat
2012-12-06 22:02 ` Steven Rostedt
2012-12-07 17:33 ` Srivatsa S. Bhat [this message]
[not found] ` <20121207200014.GB13238@redhat.com>
2012-12-10 18:21 ` Oleg Nesterov
2012-12-10 19:07 ` Steven Rostedt
2012-12-07 19:56 ` Oleg Nesterov
2012-12-07 20:25 ` Srivatsa S. Bhat
2012-12-07 20:59 ` Oleg Nesterov
2012-12-05 19:07 ` Oleg Nesterov
2012-12-05 19:16 ` Srivatsa S. Bhat
2012-12-05 18:43 ` [RFC PATCH v2 02/10] CPU hotplug: Provide APIs for "full" " Srivatsa S. Bhat
2012-12-05 19:01 ` Srivatsa S. Bhat
2012-12-05 20:31 ` Srivatsa S. Bhat
2012-12-05 20:57 ` Tejun Heo
2012-12-06 4:31 ` Srivatsa S. Bhat
2012-12-05 18:43 ` [RFC PATCH v2 03/10] CPU hotplug: Convert preprocessor macros to static inline functions Srivatsa S. Bhat
2012-12-05 18:43 ` [RFC PATCH v2 04/10] smp, cpu hotplug: Fix smp_call_function_*() to prevent CPU offline properly Srivatsa S. Bhat
2012-12-05 18:43 ` [RFC PATCH v2 05/10] smp, cpu hotplug: Fix on_each_cpu_*() " Srivatsa S. Bhat
2012-12-05 18:44 ` [RFC PATCH v2 06/10] sched, cpu hotplug: Use stable online cpus in try_to_wake_up() & select_task_rq() Srivatsa S. Bhat
2012-12-05 18:44 ` [RFC PATCH v2 07/10] kick_process(), cpu-hotplug: Prevent offlining of target CPU properly Srivatsa S. Bhat
2012-12-05 18:44 ` [RFC PATCH v2 08/10] yield_to(), cpu-hotplug: Prevent offlining of other CPUs properly Srivatsa S. Bhat
2012-12-05 18:44 ` [RFC PATCH v2 09/10] kvm, vmx: Add full atomic synchronization with CPU Hotplug Srivatsa S. Bhat
2012-12-05 18:45 ` [RFC PATCH v2 10/10] cpu: No more __stop_machine() in _cpu_down() Srivatsa S. Bhat
2012-12-05 19:08 ` Oleg Nesterov
2012-12-05 19:12 ` Srivatsa S. Bhat
[not found] <20121205131038.17383.55472.stgit@srivatsabhat.in.ibm.com>
[not found] ` <20121205131136.17383.23318.stgit@srivatsabhat.in.ibm.com>
[not found] ` <20121205142316.GI3885@mtj.dyndns.org>
[not found] ` <20121205164640.GA7382@redhat.com>
[not found] ` <20121205165356.GL3885@mtj.dyndns.org>
2012-12-05 18:15 ` [RFC PATCH v2 01/10] CPU hotplug: Provide APIs for "light" atomic readers to prevent CPU offline Oleg Nesterov
2012-12-05 18:27 ` Tejun Heo
2012-12-05 18:32 ` Srivatsa S. Bhat
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=50C2285A.60806@linux.vnet.ibm.com \
--to=srivatsa.bhat@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=amit.kucheria@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=namhyung@kernel.org \
--cc=nikunj@linux.vnet.ibm.com \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=rjw@sisk.pl \
--cc=rostedt@goodmis.org \
--cc=rusty@rustcorp.com.au \
--cc=sbw@mit.edu \
--cc=tglx@linutronix.de \
--cc=tj@kernel.org \
--cc=vincent.guittot@linaro.org \
--cc=wangyun@linux.vnet.ibm.com \
--cc=xiaoguangrong@linux.vnet.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.