linux-kernel - Re: [RFC, PATCH] cfq-iosched: remove redundant queuing detection code

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 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:	Tue, 10 Nov 2009 10:55:47 -0500
From:	Jeff Moyer <jmoyer@...hat.com>
To:	Jens Axboe <jens.axboe@...cle.com>
Cc:	Corrado Zoccolo <czoccolo@...il.com>,
	Linux-Kernel <linux-kernel@...r.kernel.org>,
	aaronc@...ato.unsw.edu.au
Subject: Re: [RFC, PATCH] cfq-iosched: remove redundant queuing detection code

Jens Axboe <jens.axboe@...cle.com> writes:

>> Why don't we simply use the value configured via the queue_depth sysfs
>> file?
>
> First of all, that only covers SCSI. We could do that by having the tag
> on/off functions set the same flag. But even for such devices, actual
> tag depth is dependent upon what other devices are on the controller
> (since it's often a shared map) and may not even be statically
> detectable in the sense that actual depth is only really seen when the
> device returns busy on a queue attempt.
>
> In most cases it would work fine, but the dynamic detection is more
> reliable. The sysfs setting in reality is max setting.

OK, thanks for the patient explanation, Jens!

Cheers,
Jeff
--
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/