From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Tom Yan <tom.ty89@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
linux-scsi@vger.kernel.org, Karel Zak <kzak@redhat.com>,
util-linux@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: optimal io size / custom alignment
Date: Tue, 16 Jun 2015 17:28:20 -0400 [thread overview]
Message-ID: <yq1d20vfimj.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <CAGnHSEkBXevNmrL7NFO=nKekZdZE6KtzjGvA8sM=onjUfd8KHQ@mail.gmail.com> (Tom Yan's message of "Wed, 17 Jun 2015 03:26:20 +0800")
>>>>> "Tom" == Tom Yan <tom.ty89@gmail.com> writes:
Tom> All drives I have are flash drives so none of them reports 4k
Tom> physical sectors.
There are plenty of SSDs that report 4K physical sectors, fwiw.
Tom> The usb-storage driver does not read vpd so it won't be a thing,
Tom> but the the uas driver does.
We gave up on USB-SATA bridges long ago. Their designers appear to have
a pretty comprehensive misunderstanding of both the ATA and SCSI
protocols.
We had higher hopes for UAS since it provided a clean slate. So far,
however, the results are equally discouraging.
Tom> I just feel like the kernel shouldn't bind values from totally
Tom> different source (raid stripe vs vpd limit) to the same variable.
RAID devices communicate the stripe width through the Block Limits VPD.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2015-06-16 21:28 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAGnHSE=gtd2WVcxOBoyfqnp3QtT4RHfK356GHastBbiK5mtmFA@mail.gmail.com>
[not found] ` <20150615133154.GV1992@ws.net.home>
[not found] ` <CAGnHSEm6wDq_EjJXYwqV2Tt2868DbR0bNRYvevhN1AM4qJpaPw@mail.gmail.com>
[not found] ` <20150616094320.GX1992@ws.net.home>
[not found] ` <20150616094320.GX1992-xkT7n84Rsxv/9pzu0YdTqQ@public.gmane.org>
2015-06-16 10:22 ` optimal io size / custom alignment Tom Yan
[not found] ` <yq1zj3zfuna.fsf@sermon.lab.mkp.net>
[not found] ` <yq1zj3zfuna.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2015-06-16 19:26 ` Tom Yan
2015-06-16 21:28 ` Martin K. Petersen [this message]
[not found] ` <yq1d20vfimj.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2015-06-17 9:49 ` Tom Yan
[not found] ` <CAGnHSEnMgivXU_0gDaOkHFkbc=Ve8PaPR0ho8+VhdcUuNu89Gw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-06-18 21:01 ` Martin K. Petersen
[not found] ` <yq1a8vwenog.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2015-06-20 16:01 ` Tom Yan
[not found] ` <CAGnHSE=DGa24TPox8wp4k264jnXjMOq7kzf-tCRf1eJt9kN0ZQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-06-21 0:12 ` Martin K. Petersen
2015-06-22 14:32 ` Alan Stern
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=yq1d20vfimj.fsf@sermon.lab.mkp.net \
--to=martin.petersen@oracle.com \
--cc=kzak@redhat.com \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=tom.ty89@gmail.com \
--cc=util-linux@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