From: Venki Pallipadi <venki@google.com>
To: Tony Luck <tony.luck@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
Andrew Morton <akpm@linux-foundation.org>,
KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Mike Travis <travis@sgi.com>,
"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
"Paul E. McKenney" <paul.mckenney@linaro.org>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Avoid mask based num_possible_cpus and num_online_cpus -v5
Date: Mon, 13 Feb 2012 12:04:59 -0800 [thread overview]
Message-ID: <CABeCy1aky-_CM-24r8u6yK65Om8aKyOHhuW0wgi-nVZf1Htqag@mail.gmail.com> (raw)
In-Reply-To: <CA+8MBbJcTgj7X-7RZAgWk8a3Qyaz1FxFzu3ZLk-8LHKD7M8h-Q@mail.gmail.com>
On Mon, Feb 13, 2012 at 11:54 AM, Tony Luck <tony.luck@gmail.com> wrote:
> On Thu, Feb 2, 2012 at 12:03 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
>> IIRC playing with 3 archs boot code seemed like a recipe for disaster.
>> Feel free to try to fix this in -next though, and see what breaks...
>
> ia64 is what breaks ... well not actually broken ... but some very
> weird delays that
> show up in different places depending on whether this patch is present.
>
> First linux-next kernel to be blessed with this patch was
> next-20120210. Booting it
> I see:
> [ 7.164233] Switching to clocksource itc
> [ 146.077315] pnp: PnP ACPI init
>
> An ugly 138.913 second delay. Digging in the code showed that the bad bits
> happened inside stop_machine()
>
> Reverting just this patch makes this big delay disappear:
>
> [ 32.780232] Switching to clocksource itc
> [ 32.832100] pnp: PnP ACPI init
>
> but notice that it takes 25 extra seconds to get to this point in the
> boot (and while
> we expect to save some time by not re-computing num_online_cpus each time we
> need it ... this looks to be a lot more than I'd expect!)
>
> -Tony
What is NR_CPUS set to here? And how many actual CPUs are there on this machine?
next prev parent reply other threads:[~2012-02-13 20:05 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-18 2:07 [PATCH] Avoid mask based num_possible_cpus and num_online_cpus Venkatesh Pallipadi
2012-01-18 5:55 ` KOSAKI Motohiro
2012-01-18 18:52 ` Venki Pallipadi
2012-01-18 19:20 ` KOSAKI Motohiro
2012-01-19 20:01 ` Venkatesh Pallipadi
2012-01-19 20:40 ` KOSAKI Motohiro
2012-01-21 1:01 ` Venki Pallipadi
2012-01-19 20:43 ` Srivatsa S. Bhat
2012-01-20 23:09 ` Venki Pallipadi
2012-01-20 23:45 ` KOSAKI Motohiro
2012-01-20 23:55 ` Venki Pallipadi
2012-01-23 5:22 ` Srivatsa S. Bhat
2012-01-23 19:28 ` Venki Pallipadi
2012-01-24 2:34 ` [PATCH] Avoid mask based num_possible_cpus and num_online_cpus -v3 Venkatesh Pallipadi
2012-01-24 19:22 ` Srivatsa S. Bhat
2012-01-24 19:30 ` KOSAKI Motohiro
2012-01-24 21:01 ` Venki Pallipadi
2012-01-24 23:25 ` [PATCH] Avoid mask based num_possible_cpus and num_online_cpus -v4 Venkatesh Pallipadi
2012-01-26 17:22 ` Srivatsa S. Bhat
2012-01-26 17:27 ` Srivatsa S. Bhat
2012-01-26 21:25 ` KOSAKI Motohiro
2012-01-26 23:22 ` Andrew Morton
2012-01-27 23:58 ` Venki Pallipadi
2012-02-01 0:17 ` [PATCH] Avoid mask based num_possible_cpus and num_online_cpus -v5 Venkatesh Pallipadi
2012-02-01 22:01 ` Andrew Morton
2012-02-02 20:03 ` Rusty Russell
2012-02-02 20:19 ` Andrew Morton
2012-02-02 21:00 ` Venki Pallipadi
2012-02-13 19:54 ` Tony Luck
2012-02-13 20:04 ` Venki Pallipadi [this message]
2012-02-13 20:25 ` Srivatsa S. Bhat
2012-02-13 20:43 ` Venki Pallipadi
2012-02-13 20:55 ` Srivatsa S. Bhat
2012-02-13 20:44 ` Srivatsa S. Bhat
2012-02-13 21:57 ` Tony Luck
2012-02-14 9:25 ` Rusty Russell
2012-02-14 21:35 ` Srivatsa S. Bhat
2012-02-14 23:00 ` Tony Luck
2012-02-14 22:49 ` [PATCH 0/3] Cleanup raw handling of online/possible map Venkatesh Pallipadi
2012-02-14 22:49 ` [PATCH 1/3] hexagon: Avoid raw handling of cpu_possible_map Venkatesh Pallipadi
2012-02-14 22:49 ` [PATCH 2/3] mips: Avoid raw handling of cpu_possible_map/cpu_online_map Venkatesh Pallipadi
2012-02-27 22:19 ` David Daney
2012-02-14 22:49 ` [PATCH 3/3] um: Avoid raw handling of cpu_online_map Venkatesh Pallipadi
2012-02-27 21:55 ` [PATCH] Avoid mask based num_possible_cpus and num_online_cpus -v5 David Daney
2012-02-27 22:07 ` Andrew Morton
2012-02-27 22:16 ` David Daney
2012-03-01 18:32 ` Venki Pallipadi
2012-02-28 5:01 ` Stephen Rothwell
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