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From: Boaz Harrosh <bharrosh@panasas.com>
To: Kai Makisara <Kai.Makisara@kolumbus.fi>
Cc: Lukas Kolbe <lkolbe@techfak.uni-bielefeld.de>,
	linux-scsi@vger.kernel.org
Subject: Re: After memory pressure: can't read from tape anymore
Date: Tue, 30 Nov 2010 18:44:51 +0200	[thread overview]
Message-ID: <4CF52A03.2000704@panasas.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1011301821210.9731@kai.makisara.local>

On 11/30/2010 06:23 PM, Kai Makisara wrote:
> On Tue, 30 Nov 2010, Boaz Harrosh wrote:
> 
>> On 11/30/2010 03:31 PM, Lukas Kolbe wrote:
>>> On Mon, 2010-11-29 at 19:09 +0200, Kai Makisara wrote:
>>>
> ....
>> It looks like something is broken/old-code in sr. Most important LLDs
>> and block-layer scsi-ml fully support sg-chaining that effectively are
>> able to deliver limitless (Only limited by HW) sg sizes. It looks like
>> sr has some code that tries to allocate contiguous buffers larger than
>> PAGE_SIZE. Why does it do that? It should not be necessary any more.
>>
> The relevant driver is st 

Sorry I meant st, yes.

> and it use sg chaining when necessary. I tried 
> to explain that the effective limit in this case comes from mptsas. I 
> don't know if it is HW limit or driver limit.
> 

Than I don't understand where is the failing allocation. Where in the
code path anyone is trying to allocate something bigger then a page?
Please explain?

> Kai
> 

Thanks
Boaz

  reply	other threads:[~2010-11-30 16:44 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-28 19:15 After memory pressure: can't read from tape anymore Lukas Kolbe
2010-11-29 17:09 ` Kai Makisara
2010-11-30 13:31   ` Lukas Kolbe
2010-11-30 16:10     ` Boaz Harrosh
2010-11-30 16:23       ` Kai Makisara
2010-11-30 16:44         ` Boaz Harrosh [this message]
2010-11-30 17:04           ` Kai Makisara
2010-11-30 17:24             ` Boaz Harrosh
2010-11-30 19:53               ` Kai Makisara
2010-12-01  9:40                 ` Lukas Kolbe
2010-12-02 11:17                   ` Desai, Kashyap
2010-12-02 16:22                     ` Kai Makisara
2010-12-02 18:14                       ` Desai, Kashyap
2010-12-02 20:25                         ` Kai Makisara
2010-12-05 10:44                           ` Lukas Kolbe
2010-12-03 10:13                       ` FUJITA Tomonori
2010-12-03 10:45                         ` Desai, Kashyap
2010-12-03 11:11                           ` FUJITA Tomonori
2010-12-02 10:01                 ` Lukas Kolbe
2010-12-03  9:44               ` FUJITA Tomonori
2010-11-30 16:20     ` Kai Makisara
2010-12-01 17:06       ` Lukas Kolbe
2010-12-02 16:41         ` Kai Makisara
2010-12-06  7:59           ` Kai Makisara
2010-12-06  8:50             ` FUJITA Tomonori
2010-12-06  9:36             ` Lukas Kolbe
2010-12-06 11:34               ` Bjørn Mork
2010-12-08 14:19               ` Lukas Kolbe
2010-12-03 12:27   ` FUJITA Tomonori
2010-12-03 14:59     ` Kai Mäkisara
2010-12-03 15:06       ` James Bottomley
2010-12-03 17:03         ` Lukas Kolbe
2010-12-03 18:10           ` James Bottomley
2010-12-05 10:53             ` Lukas Kolbe
2010-12-05 12:16               ` FUJITA Tomonori
2010-12-14 20:35             ` Vladislav Bolkhovitin
2010-12-14 22:23               ` Stephen Hemminger
2010-12-15 16:27                 ` Vladislav Bolkhovitin

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