linux-kernel - Re: [PATCH v6 04/46] percpu_rwlock: Implement the core design of Per-CPU Reader-Writer Locks

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]

Date:	Mon, 18 Feb 2013 22:16:05 +0530
From:	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>
To:	Steven Rostedt <rostedt@...dmis.org>
CC:	Michel Lespinasse <walken@...gle.com>, tglx@...utronix.de,
	peterz@...radead.org, tj@...nel.org, oleg@...hat.com,
	paulmck@...ux.vnet.ibm.com, rusty@...tcorp.com.au,
	mingo@...nel.org, akpm@...ux-foundation.org, namhyung@...nel.org,
	wangyun@...ux.vnet.ibm.com, xiaoguangrong@...ux.vnet.ibm.com,
	rjw@...k.pl, sbw@....edu, fweisbec@...il.com,
	linux@....linux.org.uk, nikunj@...ux.vnet.ibm.com,
	linux-pm@...r.kernel.org, linux-arch@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linuxppc-dev@...ts.ozlabs.org, netdev@...r.kernel.org,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	vincent.guittot@...aro.org
Subject: Re: [PATCH v6 04/46] percpu_rwlock: Implement the core design of
 Per-CPU Reader-Writer Locks

On 02/18/2013 10:01 PM, Steven Rostedt wrote:
> On Mon, 2013-02-18 at 21:51 +0530, Srivatsa S. Bhat wrote:
>> Hi Michel,
> 
>> Yes.. I don't think we can avoid that. Moreover, since we _want_ unfair
>> reader/writer semantics to allow flexible locking rules and guarantee
>> deadlock-safety, having a recursive reader side is not even an issue, IMHO.
> 
> Recursive unfair reader lock may guarantee deadlock-safety, but
> remember, it adds a higher probability of live-locking the write_lock.
> Which is another argument to keep this separate to cpu hotplug only.
> 

True.
 
Regards,
Srivatsa S. Bhat

--
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/