From: Andrew Morton <akpm@linux-foundation.org>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Venkatesh Pallipadi <venki@google.com>,
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: Thu, 2 Feb 2012 12:19:12 -0800 [thread overview]
Message-ID: <20120202121912.c82a185e.akpm@linux-foundation.org> (raw)
In-Reply-To: <87d39xj955.fsf@rustcorp.com.au>
On Fri, 03 Feb 2012 06:33:02 +1030
Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Wed, 1 Feb 2012 14:01:25 -0800, Andrew Morton <akpm@linux-foundation.org> wrote:
> > > Though most of the callers of these two routines are init time (with few
> > > exceptions of runtime calls), it is cleaner to use variables
> > > and not go through this repeated mask based calculation.
> >
> > Looks good to me.
>
> But, I wonder who's asking num_possible_cpus(). It's not a very useful
> thing to know, though some arch's "know" it's contiguous, so can cheat.
>
> Optimizing it seems particularly foolish.
We're fools for optimisations!
> We either audit and wean
> everyone off who's using it incorrectly, or insist on contiguous CPU
> numbers and drop the mask altogether.
drivers/block/nvme.c looks like it's assuming a contiguous map. Maybe
also drivers/scsi/bnx2fc (wtf?). I didn't see anything else outside
arch code.
next prev parent reply other threads:[~2012-02-02 20:19 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 [this message]
2012-02-02 21:00 ` Venki Pallipadi
2012-02-13 19:54 ` Tony Luck
2012-02-13 20:04 ` Venki Pallipadi
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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