From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Ramya Desai <ramya.desai@gmail.com>,
James Bottomley <James.Bottomley@suse.de>,
Jens Axboe <jens.axboe@oracle.com>,
USB list <linux-usb@vger.kernel.org>,
SCSI development list <linux-scsi@vger.kernel.org>,
Greg KH <greg@kroah.com>
Subject: Re: Maximum data size in a single transfer for MS driver
Date: Thu, 25 Feb 2010 14:05:58 -0500 [thread overview]
Message-ID: <yq1iq9lkueh.fsf@sermon.lab.mkp.net> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1002251324200.1686-100000@iolanthe.rowland.org> (Alan Stern's message of "Thu, 25 Feb 2010 13:28:13 -0500 (EST)")
>>>>> "Alan" == Alan Stern <stern@rowland.harvard.edu> writes:
Alan> Why is max_sectors changed? If it is already smaller than the new
Alan> value of max_hw_sectors, shouldn't it remain the same?
We have a lot of legacy device drivers kicking around in the tree so the
default max request size remains the conservative SAFE_MAX_SECTORS
(255).
When a low level driver explicitly tells us that it can support bigger
requests we take the opportunity to increase the soft limit to the block
layer default (1024).
Also, this function is generally called at block device creation time so
it's not like we're overwriting an existing user setting.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2010-02-25 19:06 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-17 12:37 Maximum data size in a single transfer for MS driver Ramya Desai
[not found] ` <3e7aae31002170437i52ba4ba1w10c1ff224d9b37ef-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-02-17 15:02 ` James Bottomley
2010-02-18 8:46 ` Ramya Desai
2010-02-18 15:47 ` James Bottomley
[not found] ` <1266508049.4355.37.camel-0iu6Cu4xQGLYCGPCin2YbQ@public.gmane.org>
2010-02-18 16:24 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1002181115120.1294-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-18 16:30 ` James Bottomley
[not found] ` <1266510627.4355.41.camel-0iu6Cu4xQGLYCGPCin2YbQ@public.gmane.org>
2010-02-18 16:51 ` Alan Stern
2010-02-19 12:43 ` Ramya Desai
2010-02-19 14:26 ` James Bottomley
2010-02-22 12:50 ` Ramya Desai
[not found] ` <3e7aae31002220450o6f83d2f3n45c795d70ef01f72-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2010-02-22 13:06 ` James Bottomley
2010-02-22 14:15 ` Ramya Desai
2010-02-22 17:44 ` Alan Stern
2010-02-22 18:07 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1002221232160.1251-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-23 15:29 ` Ramya Desai
2010-02-23 16:49 ` Alan Stern
2010-02-23 17:00 ` Martin K. Petersen
2010-02-23 18:01 ` Alan Stern
[not found] ` <Pine.LNX.4.44L0.1002231253320.1308-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-24 13:07 ` Ramya Desai
2010-02-24 13:12 ` Jens Axboe
2010-02-24 16:30 ` Alan Stern
2010-02-24 19:07 ` Jens Axboe
2010-02-25 14:47 ` Ramya Desai
2010-02-25 14:44 ` Ramya Desai
2010-02-25 16:37 ` Alan Stern
2010-02-25 16:49 ` Martin K. Petersen
2010-02-25 16:53 ` Martin K. Petersen
2010-02-25 17:54 ` Jens Axboe
[not found] ` <yq1zl2xl0j3.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2010-02-25 18:28 ` Alan Stern
2010-02-25 19:05 ` Martin K. Petersen [this message]
[not found] ` <yq1iq9lkueh.fsf-+q57XtR/GgMb6DWv4sQWN6xOck334EZe@public.gmane.org>
2010-02-25 19:47 ` Alan Stern
2010-02-26 3:37 ` Martin K. Petersen
[not found] ` <Pine.LNX.4.44L0.1002251132170.1686-100000-IYeN2dnnYyZXsRXLowluHWD2FQJk+8+b@public.gmane.org>
2010-02-25 17:52 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2010-02-25 16:59 scameron
2010-02-25 17:00 ` scameron
2010-02-25 17:18 ` scameron
2010-02-25 17:28 ` Martin K. Petersen
2010-02-25 17:41 ` Boaz Harrosh
2010-02-25 17:58 ` Martin K. Petersen
2010-02-25 19:07 ` Martin K. Petersen
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=yq1iq9lkueh.fsf@sermon.lab.mkp.net \
--to=martin.petersen@oracle.com \
--cc=James.Bottomley@suse.de \
--cc=greg@kroah.com \
--cc=jens.axboe@oracle.com \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=ramya.desai@gmail.com \
--cc=stern@rowland.harvard.edu \
/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