From: Tony Battersby <tonyb@cybernetics.com>
To: Bart Van Assche <bvanassche@acm.org>,
dgilbert@interlog.com, James Bottomley <jejb@linux.vnet.ibm.com>,
linux-scsi@vger.kernel.org, linux-block@vger.kernel.org,
linux-api@vger.kernel.org
Cc: martin.petersen@oracle.com, hare@suse.de, Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH v3 00/20] sg: add v4 interface
Date: Fri, 9 Aug 2019 09:28:54 -0400 [thread overview]
Message-ID: <cd26b3a8-5943-6e3b-9e81-4cfd280777c1@cybernetics.com> (raw)
In-Reply-To: <517f279d-38ec-79eb-cc7f-77d1e873ea62@acm.org>
On 8/8/19 6:25 PM, Bart Van Assche wrote:
> On 8/8/19 2:37 PM, Tony Battersby wrote:
>> On 8/8/19 5:08 PM, Douglas Gilbert wrote:
>>> *** Tony Battersby is a sg driver power user. He has lamented wading through
>>> very large logs looking for some hint of why the sg driver is playing
>>> up. He has stated the strong preference for more, not less, ioctls.
>>>
>> One of the reasons ioctls have a bad reputation is because they can be
>> used to implement poorly-thought-out interfaces. So kernel maintainers
>> push back on adding new ioctls. But the push back isn't about the
>> number of ioctls, it is about the poor interfaces. My advice was that
>> in general, to implement a given API, it would be better to add more
>> ioctls with a simple interface for each one rather than to add fewer
>> extremely complex multiplexing ioctls.
> Hi Tony,
>
> What is your motivation to use the SG_IO API? Is it controlling SMR
> drives or are you using SG_IO for another reason? I'm asking because
> depending on the use case there may be a better solution than using the
> SG_IO API.
>
> Thanks,
>
> Bart.
>
Actually I used the asynchronous write()/read()/poll() sg interface to
implement RAID-like functionality for tape drives and medium changers,
in a commercial product that has been around since 2002. These days our
products use a lot more disk I/O than tape I/O, so I don't write much
new code using the sg interface anymore, although that code is still
there and has to be maintained as needed. So I don't have any immediate
plans to use any of the new sgv4 features being introduced, and
unfortunately I am way too busy to even give it a good review...
Tony Battersby
Cybernetics
next prev parent reply other threads:[~2019-08-09 13:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190807114252.2565-1-dgilbert@interlog.com>
2019-08-08 19:10 ` [PATCH v3 00/20] sg: add v4 interface James Bottomley
2019-08-08 21:08 ` Douglas Gilbert
2019-08-08 21:37 ` Tony Battersby
2019-08-08 22:25 ` Bart Van Assche
2019-08-09 13:28 ` Tony Battersby [this message]
2019-08-08 23:00 ` James Bottomley
2019-08-14 4:19 ` Douglas Gilbert
2019-08-15 17:30 ` Bart Van Assche
2019-08-16 15:59 ` Douglas Gilbert
2019-08-16 17:19 ` Greg KH
2019-08-16 18:10 ` Bart Van Assche
2019-08-16 18:44 ` Douglas Gilbert
2019-08-12 15:23 ` Christoph Hellwig
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=cd26b3a8-5943-6e3b-9e81-4cfd280777c1@cybernetics.com \
--to=tonyb@cybernetics.com \
--cc=arnd@arndb.de \
--cc=bvanassche@acm.org \
--cc=dgilbert@interlog.com \
--cc=hare@suse.de \
--cc=jejb@linux.vnet.ibm.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
/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).