From: Tejun Heo <htejun@gmail.com>
To: Elias Oltmanns <eo@nebensachen.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
James Bottomley <James.Bottomley@HansenPartnership.com>,
Jens Axboe <jens.axboe@oracle.com>,
linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: Prevent busy looping
Date: Thu, 12 Jun 2008 22:43:29 +0900 [thread overview]
Message-ID: <48512801.7090502@gmail.com> (raw)
In-Reply-To: <87d4mmubvf.fsf@denkblock.local>
Elias Oltmanns wrote:
> Since I'm a little confused by your comment, please explain again. Do
> you mean to say that busy looping doesn't lock up the machine in general
> or merely in the case of a simplex configuration?
It busy loops but it won't lock up as command completion is the loop
breaker and command completion comes via IRQ and the busy looping
doesn't happen solely in the IRQ context. Still needs to be fixed tho.
Anyways, this is only limited to ->qc_defer for simplex and the reason
why there's busy loop is because we're trying to schedule two
independent hosts and SCSI midlayer (of course) doesn't have the notion
of cross host deferring.
Thanks.
--
tejun
next prev parent reply other threads:[~2008-06-12 13:43 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080416151305.8788.63912.stgit@denkblock.local>
[not found] ` <20080416163152.GK12774@kernel.dk>
[not found] ` <87r6d5l9pb.fsf@denkblock.local>
[not found] ` <20080417071335.GR12774@kernel.dk>
2008-04-17 8:50 ` Prevent busy looping Elias Oltmanns
2008-06-11 7:11 ` Tejun Heo
2008-06-11 7:05 ` Alan Cox
2008-06-11 8:03 ` Tejun Heo
2008-06-12 3:06 ` Tejun Heo
2008-06-12 11:32 ` Elias Oltmanns
2008-06-12 13:43 ` Tejun Heo [this message]
2008-06-12 14:18 ` James Bottomley
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=48512801.7090502@gmail.com \
--to=htejun@gmail.com \
--cc=James.Bottomley@HansenPartnership.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=eo@nebensachen.de \
--cc=jens.axboe@oracle.com \
--cc=linux-ide@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).