Can multiple concurrent SCSI Pass Through (Direct) cause system lockup?

NTDEV
1

Hello,

In my upper disk filter when I send multiple SPTI DIRECT from different threads in the driver, I see system lock up. I cannot break via WinDbg even ( I have debugger connected the whole time).

I am sending about 500KB data using SPTIDirect every few minutes (30 mins or more) to the FC storage controller. I also have a few more threads in the driver that are doing SPTID using much smaller buffer, but they are called more frequently (at less than minute or so).

The hang usually occurs when I see multiple SPTID calls getting queued to the port driver at the same time, atleast thats what I see happening in the debugger output. There is no issue when only the smaller buffer SPTID is performed, the problem starts occurring when the large SPTID buffer gets in the picture.

Any observations on this behavior?

Do I need to serialize my calls for SPTID?

TIA!

2

From what IRQL are you sending it?

3

Hello Alex,

I am sending all SPTDs at IRQL 0 (PASSIVE_LEVEL).

The requests are build using IoBuildDeviceIoControlRequest, and the function that finally submits it to the lower driver has PAGED_CODE() macro as well. Since I am running checked build with debugger attached, it would actually assert in the debugger if IRQL is > 0.

TIA!

4

Have you tried setting breakpoints where you send the large request, then step through your code after you send the first one?

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of xxxxx@yahoo.com
Sent: Monday, July 29, 2013 7:31 PM
To: Windows System Software Devs Interest List
Subject: RE:[ntdev] Can multiple concurrent SCSI Pass Through (Direct) cause system lockup?

Hello Alex,

I am sending all SPTDs at IRQL 0 (PASSIVE_LEVEL).

The requests are build using IoBuildDeviceIoControlRequest, and the function that finally submits it to the lower driver has PAGED_CODE() macro as well. Since I am running checked build with debugger attached, it would actually assert in the debugger if IRQL is > 0.

TIA!

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