From: Arnd Bergmann <arnd@arndb.de>
To: paulmck@linux.vnet.ibm.com
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>, Ingo Molnar <mingo@elte.hu>,
LKML <linux-kernel@vger.kernel.org>,
Manfred Spraul <manfred@colorfullife.com>
Subject: Re: [PATCH V4 1/1] rcu: introduce kfree_rcu()
Date: Tue, 15 Mar 2011 14:07:24 +0100 [thread overview]
Message-ID: <201103151407.24800.arnd@arndb.de> (raw)
In-Reply-To: <20110315121941.GD2167@linux.vnet.ibm.com>
On Tuesday 15 March 2011, Paul E. McKenney wrote:
> And it makes use of statically allocated structures a bit clunky.
How do statically allocated structures relate to this? I would
expect that you never call kfree_rcu on them, so it shouldn't
matter.
> Yet another approach is to use the low-order bit of the rcu_head pointer,
> given that the rcu_head structure does have to be aligned. If this bit
> is set, then the function pointer could be interpreted as an offset.
> This approach might also allow a slab_free_rcu() to be constructed, given
> that the full 32 bits of the function pointer would be available.
> For example, if the upper 16 bits are zero, the low-order 16 bits are
> the offset. If the upper 16 bits are 0x1, then the low-order 16 bits
> might be an index that selects the desired slab cache.
This solution sounds like a clear improvement over the patch that Lai
Jiangshan posted, without any downsides.
Arnd
next prev parent reply other threads:[~2011-03-15 13:07 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-15 9:46 [PATCH V4 1/1] rcu: introduce kfree_rcu() Lai Jiangshan
2011-03-15 10:15 ` Arnd Bergmann
2011-03-15 11:27 ` Paul E. McKenney
2011-03-15 12:02 ` Arnd Bergmann
2011-03-15 12:19 ` Paul E. McKenney
2011-03-15 13:07 ` Arnd Bergmann [this message]
2011-03-16 2:58 ` Lai Jiangshan
2011-03-16 4:38 ` Paul E. McKenney
2011-03-16 4:02 ` Paul E. McKenney
2011-03-18 3:15 ` [PATCH V5 " Lai Jiangshan
2011-03-18 8:14 ` Arnd Bergmann
2011-03-16 2:23 ` [PATCH V4 " Lai Jiangshan
2011-03-15 11:30 ` Paul E. McKenney
2011-03-16 2:50 ` Lai Jiangshan
2011-03-16 4:29 ` Paul E. McKenney
2011-03-15 13:11 ` Eric Dumazet
2011-03-16 4:03 ` Paul E. McKenney
2011-03-17 9:28 ` Lai Jiangshan
2011-03-17 17:50 ` Paul E. McKenney
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