linux-kernel - Re: [PATCH 1/13] BC: atomic_dec_and_lock

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: <45549889.5000300@legoater.org>
Date:	Fri, 10 Nov 2006 16:19:37 +0100
From:	Cedric Le Goater <cedric@...oater.org>
To:	Kirill Korotaev <dev@...ru>
CC:	Andrew Morton <akpm@...l.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Alan Cox <alan@...rguk.ukuu.org.uk>, xemul@...nvz.org,
	devel@...nvz.org, oleg@...sign.ru, hch@...radead.org,
	matthltc@...ibm.com, ckrm-tech@...ts.sourceforge.net
Subject: Re: [PATCH 1/13] BC: atomic_dec_and_lock_irqsave() helper

Hello Kirill, Hello Pavel,

Kirill Korotaev wrote:
> Oleg Nesterov noticed to me that the construction like
> (used in beancounter patches and free_uid()):
> 
>   local_irq_save(flags);
>   if (atomic_dec_and_lock(&refcnt, &lock))
> 	  ...
> 
> is not that good for preemtible kernels, since with preemption
> spin_lock() can schedule() to reduce latency. However, it won't schedule
> if interrupts are disabled.
> 
> So this patch introduces atomic_dec_and_lock_irqsave() as a logical
> counterpart to atomic_dec_and_lock().

You should probably send that one independently from the BC 
patchset. 

C.
-
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/