Verifier affects lookaside lists (?)

NTDEV
1

Hello

I have a couple of lookaside lists in my driver running under srv03.
While in the debugger, I used the !lookaside extension to watch the
stats, and it showed an expected good
hit rate, allocations, etc. However, when I enabled the verifier for my
driver (/flags 0x39), the lookaside lists seemed to cease to behave as
such: the hit rate stayed
at solid zero all the time, and TotalAllocates=AllocateMisses.

Is it a known limitation? Anyone else experienced that?

Thanks,

  • Vitaly
2

Verifier forces allocations from lookaside lists to go through the pool (as
the list depth is forced to 0), as I learned to my cost. Walter Oney notes
this in chapter 3 of his second edition book.

Philip Lukidis < mailto:xxxxx@guillemot.com
mailto:xxxxx >
Software Engineer - Guillemot R&D inc. http://www.guillemot.com
http:</http:>
Tel: (514) 279-9960 ext:4111 Fax: (514) 279-2558
5800 St-Denis, Suite 1102, Montreal, Quebec, H2S 3L5, Canada

-----Original Message-----
From: Vitaly Vatnikov [mailto:xxxxx@relicore.com]
Sent: Monday, September 27, 2004 3:13 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Verifier affects lookaside lists (?)

Hello

I have a couple of lookaside lists in my driver running under srv03. While
in the debugger, I used the !lookaside extension to watch the stats, and it
showed an expected good
hit rate, allocations, etc. However, when I enabled the verifier for my
driver (/flags 0x39), the lookaside lists seemed to cease to behave as such:
the hit rate stayed
at solid zero all the time, and TotalAllocates=AllocateMisses.

Is it a known limitation? Anyone else experienced that?

Thanks,

- Vitaly

—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

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3

This is not a limitation, it is a feature. By making the allocation miss every time, it is easier to simulate out of memory conditions.

d

From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Vitaly Vatnikov
Sent: Monday, September 27, 2004 12:13 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Verifier affects lookaside lists (?)

Hello
?
I have a couple of lookaside lists in my driver running under srv03. While in the debugger, I used the !lookaside extension to watch the stats, and it showed an expected good
hit rate, allocations, etc. However, when I enabled the verifier for my driver (/flags 0x39),?the lookaside lists seemed to?cease to behave as such: the hit rate stayed
at solid zero all the time, and TotalAllocates=AllocateMisses.
?
Is?it a known limitation? Anyone else experienced that?
?
Thanks,
?

  • Vitaly??
    ?
    ?

Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

4

Philip and Doron - thank you for the responses: it does makes sense now.
Although, I’d prefer this feature was somehow configurable.

  • Vitaly

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Doron Holan
Sent: Monday, September 27, 2004 3:18 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] Verifier affects lookaside lists (?)

This is not a limitation, it is a feature. By making the allocation
miss every time, it is easier to simulate out of memory conditions.

d

From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Vitaly Vatnikov
Sent: Monday, September 27, 2004 12:13 PM
To: Windows System Software Devs Interest List
Subject: [ntdev] Verifier affects lookaside lists (?)

Hello
?
I have a couple of lookaside lists in my driver running under srv03.
While in the debugger, I used the !lookaside extension to watch the
stats, and it showed an expected good hit rate, allocations, etc.
However, when I enabled the verifier for my driver (/flags 0x39),?the
lookaside lists seemed to?cease to behave as such: the hit rate stayed
at solid zero all the time, and TotalAllocates=AllocateMisses.
?
Is?it a known limitation? Anyone else experienced that?
?
Thanks,
?

  • Vitaly??
    ?
    ?

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument:
‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com

Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: unknown lmsubst tag argument:
‘’ To unsubscribe send a blank email to xxxxx@lists.osr.com