linux-kernel - Re: [PATCH] block: Make CFQ default to IOPS mode on SSDs

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: <873821kww7.fsf@orebokech.com>
Date:	Tue, 09 Jun 2015 12:18:32 +0200
From:	Romain Francoise <romain@...bokech.com>
To:	Tahsin Erdogan <tahsin@...gle.com>
Cc:	Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] block: Make CFQ default to IOPS mode on SSDs

Hi,

On Tue, May 19, 2015 at 01:55:21PM -0700, Tahsin Erdogan wrote:
> --- a/block/cfq-iosched.c
> +++ b/block/cfq-iosched.c
> @@ -4460,7 +4460,7 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e)
>  	cfqd->cfq_slice[1] = cfq_slice_sync;
>  	cfqd->cfq_target_latency = cfq_target_latency;
>  	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
> -	cfqd->cfq_slice_idle = cfq_slice_idle;
> +	cfqd->cfq_slice_idle = blk_queue_nonrot(q) ? 0 : cfq_slice_idle;
>  	cfqd->cfq_group_idle = cfq_group_idle;
>  	cfqd->cfq_latency = 1;
>  	cfqd->hw_tag = -1;

Did you test this patch with regular AHCI SSD devices? Applying it on
top of v4.1-rc7 makes no difference, slice_idle is still initialized to
8 in my setup, while rotational is 0.

Isn't the elevator initialized long before the non-rotational flag is
actually set on the device (which probably happens after it's probed on
the scsi bus)?
--
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/