From: "Michal Nazarewicz" <mina86@mina86.com>
To: "Gilad Ben-Yossef" <gilad@benyossef.com>,
"Andrew Morton" <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
"Chris Metcalf" <cmetcalf@tilera.com>,
"Peter Zijlstra" <a.p.zijlstra@chello.nl>,
"Frederic Weisbecker" <fweisbec@gmail.com>,
"Russell King" <linux@arm.linux.org.uk>,
linux-mm@kvack.org, "Pekka Enberg" <penberg@kernel.org>,
"Matt Mackall" <mpm@selenic.com>,
"Rik van Riel" <riel@redhat.com>,
"Andi Kleen" <andi@firstfloor.org>,
"Sasha Levin" <levinsasha928@gmail.com>,
"Mel Gorman" <mel@csn.ul.ie>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, "Avi Kivity" <avi@redhat.com>
Subject: Re: [PATCH v5 1/8] smp: Introduce a generic on_each_cpu_mask function
Date: Thu, 05 Jan 2012 14:17:54 +0100 [thread overview]
Message-ID: <op.v7l4j4ms3l0zgt@mpn-glaptop> (raw)
In-Reply-To: <20120103142624.faf46d77.akpm@linux-foundation.org>
On Tue, 03 Jan 2012 23:26:24 +0100, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Mon, 2 Jan 2012 12:24:12 +0200
> Gilad Ben-Yossef <gilad@benyossef.com> wrote:
>
>> on_each_cpu_mask calls a function on processors specified my cpumask,
>> which may include the local processor.
>> @@ -132,6 +139,15 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info)
>> local_irq_enable(); \
>> 0; \
>> })
>> +#define on_each_cpu_mask(mask, func, info, wait) \
>> + do { \
>> + if (cpumask_test_cpu(0, (mask))) { \
>> + local_irq_disable(); \
>> + (func)(info); \
>> + local_irq_enable(); \
>> + } \
>> + } while (0)
>
> Why is the cpumask_test_cpu() call there? It's hard to think of a
> reason why "mask" would specify any CPU other than "0" in a
> uniprocessor kernel.
It may specify none. For instance, in drain_all_pages() case, if the
CPU has no pages on PCP lists, the mask will be empty and so the
cpumask_test_cpu() will return zero.
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo--
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next prev parent reply other threads:[~2012-01-05 13:17 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1325499859-2262-1-git-send-email-gilad@benyossef.com>
2012-01-02 10:24 ` [PATCH v5 1/8] smp: Introduce a generic on_each_cpu_mask function Gilad Ben-Yossef
2012-01-03 7:51 ` Michal Nazarewicz
2012-01-03 8:12 ` Gilad Ben-Yossef
2012-01-03 8:57 ` Michal Nazarewicz
2012-01-03 22:26 ` Andrew Morton
2012-01-05 13:17 ` Michal Nazarewicz [this message]
2012-01-08 16:04 ` Gilad Ben-Yossef
2012-01-02 10:24 ` [PATCH v5 2/8] arm: Move arm over to generic on_each_cpu_mask Gilad Ben-Yossef
2012-01-02 10:24 ` [PATCH v5 3/8] tile: Move tile to use " Gilad Ben-Yossef
2012-01-02 10:24 ` [PATCH v5 4/8] smp: Add func to IPI cpus based on parameter func Gilad Ben-Yossef
2012-01-03 22:34 ` Andrew Morton
2012-01-08 16:09 ` Gilad Ben-Yossef
2012-01-02 10:24 ` [PATCH v5 5/8] slub: Only IPI CPUs that have per cpu obj to flush Gilad Ben-Yossef
2012-01-02 10:24 ` [PATCH v5 6/8] fs: only send IPI to invalidate LRU BH when needed Gilad Ben-Yossef
2012-01-02 10:24 ` [PATCH v5 7/8] mm: Only IPI CPUs to drain local pages if they exist Gilad Ben-Yossef
2012-01-03 17:45 ` KOSAKI Motohiro
2012-01-03 18:58 ` Gilad Ben-Yossef
2012-01-03 22:02 ` KOSAKI Motohiro
2012-01-05 14:20 ` Mel Gorman
2012-01-05 14:40 ` Russell King - ARM Linux
2012-01-05 15:24 ` Peter Zijlstra
2012-01-05 16:17 ` Mel Gorman
2012-01-05 16:35 ` Russell King - ARM Linux
2012-01-05 18:35 ` Paul E. McKenney
2012-01-05 22:21 ` Mel Gorman
2012-01-06 6:06 ` Srivatsa S. Bhat
2012-01-06 10:46 ` Mel Gorman
2012-01-06 13:28 ` Greg KH
2012-01-06 14:09 ` Mel Gorman
2012-01-05 22:06 ` Andrew Morton
2012-01-05 22:31 ` Mel Gorman
2012-01-05 23:19 ` Andrew Morton
2012-01-09 17:25 ` Mel Gorman
2012-01-07 16:52 ` Paul E. McKenney
2012-01-07 17:05 ` Paul E. McKenney
2012-01-05 15:54 ` Mel Gorman
2012-01-08 16:01 ` Gilad Ben-Yossef
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