From: "Américo Wang" <xiyou.wangcong@gmail.com>
To: Cypher Wu <cypher.w@gmail.com>
Cc: "Américo Wang" <xiyou.wangcong@gmail.com>,
"Yong Zhang" <yong.zhang0@gmail.com>,
"Eric Dumazet" <eric.dumazet@gmail.com>,
linux-kernel@vger.kernel.org, netdev <netdev@vger.kernel.org>
Subject: Re: Kernel rwlock design, Multicore and IGMP
Date: Sat, 13 Nov 2010 14:35:51 +0800 [thread overview]
Message-ID: <20101113063551.GD3837@hack> (raw)
In-Reply-To: <AANLkTi=0Z1zVqCvYwKiQ8cUZoeD_rLgZ+C07GuFgA7E7@mail.gmail.com>
On Fri, Nov 12, 2010 at 07:06:47PM +0800, Cypher Wu wrote:
>>
>> Note, on Tile, it uses a little different algorithm.
>>
>
>It seems that rwlock on x86 and tile have different behavior, x86 use
>RW_LOCK_BIAS, when read_lock() it will test if the lock is 0, and if
>so then the read_lock() have to 'spinning', otherwise it dec the lock;
>when write_lock() tried it first check if lock is It seems that rwlock
>on x86 and tile have different behavior, x86 use RW_LOCK_BIAS and if
>so, set lock to 0 and continue, otherwise it will 'spinning'.
>I'm not very familiar with x86 architecture, but the code seems like
>working that way.
No, they should be the same, sorry I made a mistake in the above reply.
Although Tile uses shifts in implementation while x86 uses inc/dec,
the idea is same, either writers use higher bits and readers use
lower bits or vice-versa.
--
Live like a child, think like the god.
next prev parent reply other threads:[~2010-11-13 6:35 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AANLkTikvT=x9eBovn2-m6HLqk7wyXSAR3sc9jCQ0C6mL@mail.gmail.com>
2010-11-11 15:23 ` Kernel rwlock design, Multicore and IGMP Eric Dumazet
2010-11-11 15:32 ` Eric Dumazet
2010-11-12 3:32 ` Cypher Wu
2010-11-12 6:28 ` Américo Wang
2010-11-12 7:13 ` Américo Wang
2010-11-12 7:27 ` Eric Dumazet
2010-11-12 8:19 ` Américo Wang
2010-11-12 9:09 ` Yong Zhang
2010-11-12 9:18 ` Américo Wang
2010-11-12 11:06 ` Cypher Wu
2010-11-13 6:35 ` Américo Wang [this message]
2010-11-12 13:00 ` Yong Zhang
2010-11-13 6:28 ` Américo Wang
2010-11-12 9:22 ` Eric Dumazet
2010-11-12 9:33 ` Américo Wang
2010-11-12 13:34 ` [PATCH net-next-2.6] igmp: RCU conversion of in_dev->mc_list Eric Dumazet
2010-11-12 14:26 ` Eric Dumazet
2010-11-12 15:46 ` [PATCH net-next-2.6 V2] " Eric Dumazet
2010-11-12 21:19 ` David Miller
2010-11-13 6:44 ` Américo Wang
2010-11-13 22:54 ` Kernel rwlock design, Multicore and IGMP Peter Zijlstra
2010-11-12 11:10 ` Cypher Wu
2010-11-12 11:25 ` Eric Dumazet
2010-11-13 22:53 ` Peter Zijlstra
[not found] ` <ZXmP8hjgLHA.4648@exchange1.tad.internal.tilera.com>
2010-11-13 23:03 ` Chris Metcalf
2010-11-15 7:22 ` Cypher Wu
2010-11-15 11:18 ` Cypher Wu
2010-11-15 11:31 ` Eric Dumazet
2010-11-17 1:30 ` Cypher Wu
2010-11-17 4:43 ` Eric Dumazet
2010-11-15 14:18 ` [PATCH] arch/tile: fix rwlock so would-be write lockers don't block new readers Chris Metcalf
2010-11-15 14:52 ` Eric Dumazet
2010-11-15 15:10 ` Chris Metcalf
2010-11-22 5:39 ` Cypher Wu
2010-11-22 13:35 ` Chris Metcalf
2010-11-23 1:36 ` Cypher Wu
2010-11-23 21:02 ` Chris Metcalf
2010-11-24 2:53 ` Cypher Wu
2010-11-24 14:09 ` Chris Metcalf
2010-11-24 16:37 ` Cypher Wu
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