linux-kernel - Re: Re: [PATCH 2/2] 2.6.19-rc1-mm1 pktcdvd: bio write congestion

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] [day] [month] [year] [list]

Date:	Mon, 16 Oct 2006 21:32:37 +0200 (CEST)
From:	Peter Osterlund <petero2@...ia.com>
To:	balagi@...tmail.de
cc:	Jens Axboe <jens.axboe@...cle.com>, linux-kernel@...r.kernel.org
Subject: Re: Re: [PATCH 2/2] 2.6.19-rc1-mm1 pktcdvd: bio write congestion

On Mon, 16 Oct 2006, balagi@...tmail.de wrote:

> the congestion control will work with both code changes, but i am
> not sure, if using clear_queue_congested() and blk_congestion_wait()
> is the right thing to use here: it works on global level. Any other
> thread/driver/etc. can do a clear_queue_congested() and wake
> up anyone waiting on this global write or read wait queue, resulting to
> unneeded task switches.
> The driver local solution (own waitqueue) would prevent this.....

But it would make the driver more complex. How many extra task switches 
can you get, and how much CPU time does that consume? If it is negligible 
I think it's better to keep the code simple.

-- 
Peter Osterlund - petero2@...ia.com
http://web.telia.com/~u89404340
-
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/