Ref: Size of SrbExtension

NTDEV
1

Hi All,

I would like to know how much maximum I can ask the SrbExtensionSize in HW_INITIALIZATION_DATA. I am trying to allocate 512k and more.
Is it possible? On what factors port driver would allocate a big SrbExtension (as big as 1MB) with lets say having 20-30 outstanding IOs maximum supported by the SCSI miniport drivers or Storport miniport drivers.

Any idea is highly appreciated.

TIA,
Gurpreet

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2

Gee that is a lot of per request storage. What are you trying to do?

The srb extension buffers are going to be preallocated and added into
the contiguous common buffer space allocated for your adapter. You are
requesting 512K * (maximum number of requests) of contiguous memory.
That’s a lot to ask for.

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Gurpreet Anand
Sent: Monday, March 06, 2006 2:28 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Ref: Size of SrbExtension

Hi All,

I would like to know how much maximum I can ask the SrbExtensionSize in
HW_INITIALIZATION_DATA. I am trying to allocate 512k and more.
Is it possible? On what factors port driver would allocate a big
SrbExtension (as big as 1MB) with lets say having 20-30 outstanding IOs
maximum supported by the SCSI miniport drivers or Storport miniport
drivers.

Any idea is highly appreciated.

TIA,
Gurpreet

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3

SRB Extensions come out of common buffer - they’re allocated in a large
slab. In order to get 15MB you’d need to be able to find 15MB of
physically contiguous memory when your driver loads.

This seems really excessive. Are you trying to coallesce transfers in
your SRB extensions or something?

-p

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Gurpreet Anand
Sent: Monday, March 06, 2006 11:28 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] Ref: Size of SrbExtension

Hi All,

I would like to know how much maximum I can ask the SrbExtensionSize in
HW_INITIALIZATION_DATA. I am trying to allocate 512k and more.
Is it possible? On what factors port driver would allocate a big
SrbExtension (as big as 1MB) with lets say having 20-30 outstanding IOs
maximum supported by the SCSI miniport drivers or Storport miniport
drivers.

Any idea is highly appreciated.

TIA,
Gurpreet

Brings words and photos together (easily) with
PhotoMail
http:hoo.com> - it’s free and works with Yahoo! Mail. — Questions? First
check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256 To unsubscribe, visit the
List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer</http:>