From: Jeff Garzik <jeff@garzik.org>
To: Michael Tokarev <mjt@tls.msk.ru>
Cc: linux-scsi@vger.kernel.org
Subject: Re: disable TCQ?
Date: Thu, 28 Jun 2007 06:09:02 -0400 [thread overview]
Message-ID: <468388BE.6040809@garzik.org> (raw)
In-Reply-To: <46836F15.2040208@msgid.tls.msk.ru>
Michael Tokarev wrote:
> /sys/block/sdX/device/queue_depth file is read-write with
> libsata, but is read-only with SCSI controllers (at least
> with the ones we have -- mostly aic7xxx or mptsas).
>
> Googling for "disable tcq" gives results about {dis,en}abling
> TCQ at boot time, and also mentions ipr (which we don't have).
>
> Is there an option to control TCQ at runtime?
You have found the correct sysfs file -- but read/write access to it
requires the SCSI driver to implement the ->change_queue_depth() hook.
'grep -w' will show that not too many drivers have implemented this yet,
mostly the newer ones. For older drivers, poke around and see if there
is a driver-specific module option or somesuch.
Jeff
prev parent reply other threads:[~2007-06-28 10:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-28 8:19 disable TCQ? Michael Tokarev
2007-06-28 10:09 ` Jeff Garzik [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=468388BE.6040809@garzik.org \
--to=jeff@garzik.org \
--cc=linux-scsi@vger.kernel.org \
--cc=mjt@tls.msk.ru \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.