linux-kernel - Re: [PATCH V4 1/1] rcu: introduce kfree

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4D802578.8050603@cn.fujitsu.com>
Date:	Wed, 16 Mar 2011 10:50:32 +0800
From:	Lai Jiangshan <laijs@...fujitsu.com>
To:	paulmck@...ux.vnet.ibm.com
CC:	Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>,
	Manfred Spraul <manfred@...orfullife.com>
Subject: Re: [PATCH V4 1/1] rcu: introduce kfree_rcu()

On 03/15/2011 07:30 PM, Paul E. McKenney wrote:
> On Tue, Mar 15, 2011 at 05:46:20PM +0800, Lai Jiangshan wrote:
>> kfree_rcu() which was original proposed by Lai 2.5 years ago is one of
>> the most important RCU TODO list entries, Lai and Manfred have worked on
>> patches for this. This V4 patch is based on the Manfred's patch and
>> the V1 of Lai's patch. (These two patches are almost the same
>> in implementation, and this patch is mainly based on the Manfred's).
>>
>> Lai's V1 patch: http://lkml.org/lkml/2008/9/18/1
>> Manfred's patch: http://lkml.org/lkml/2009/1/2/115
>> RCU TODO list: http://www.kernel.org/pub/linux/kernel/people/paulmck/rcutodo.html
>>
>> This new introduced API kfree_rcu() primitive kfree()s the specified memory
>> after a RCU grace period elapses.
>>
>> It replaces many simple "call_rcu(head, simple_kfree_callback)";
>> These many simple_kfree_callback() instances just does
>>
>> 	kfree(containerof(head,struct whatever_struct,rcu_member));
>>
>> These simple_kfree_callback() instances are just duplicate code, we need
>> a generic function for them.
>>
>> And kfree_rcu() is also help for unloadable modules, kfree_rcu() does not
>> queue any function which belong to the module, so a rcu_barrier() can
>> be avoid when module exit. (If we queue any other function by call_rcu(),
>> rcu_barrier() is still needed.)
> 
> Thank you for putting this together!  It does represent a nice
> reduction in code size.
> 
> Once it settles out a bit, I intend to queue this patch.  It would be
> best if the subsystems queue their own patches using kfree_rcu() once
> this patch reaches mainline.
> 

It seems that the subsystems maintainers just Ack the patches.
I hope Ingo queue the Acked using kfree_rcu() patches into -tip,
it will help the kfree_rcu() reaches mainline earlier.

Thanks,
Lai
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/