linux-kernel - Re: [PATCH 1/2] null_blk: prevent timer handler running on a different CPU where started

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: <556DC139.4060805@fb.com>
Date:	Tue, 2 Jun 2015 08:44:09 -0600
From:	Jens Axboe <axboe@...com>
To:	Akinobu Mita <akinobu.mita@...il.com>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] null_blk: prevent timer handler running on a different
 CPU where started

On 06/01/2015 05:35 PM, Akinobu Mita wrote:
> When irqmode=2 (IRQ completion handler is timer), timer handler should
> be called on the same CPU where the timer has been started.
>
> Since completion_queues are per-cpu and the completion handler only
> touches completion_queue for local CPU, we need to prevent the handler
> from running on a different CPU where the timer has been started.
> Otherwise, the IO cannot be completed until another completion handler
> is executed on that CPU.

Thanks, applied this and 2/2, the latter seems to have been forgotten 
after our initial discussion about it.

-- 
Jens Axboe

--
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/