kern/94139: amr broken with LSILogic MegaRAID Series 428 (HP NetRAID) on 6-STABLE: reading app hangs

[Denis Eremenko <moonshade at pnhz.kz>]

>Number:         94139
>Category:       kern
>Synopsis:       amr broken with LSILogic MegaRAID Series 428 (HP NetRAID) on 6-STABLE: reading app hangs
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Mar 06 13:40:02 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Denis Eremenko <moonshade at pnhz.kz>
>Release:        FreeBSD 6.1-PRERELEASE i386
>Organization:
>Environment:


System: FreeBSD 6.1-PRERELEASE #0: Thu Feb 23 08:34:49 ALMT 2006
    root at abyss.pnhz.kz:/usr/obj/data/os/FreeBSD/src/6/src/sys/ABYSS-6



>Description:


Application hangs in D state (reading from disk) while reading from amrd on 6-STABLE.
But amr(4) from 6.0-RELEASE works fine. I suppose it was broken with "LSI MegaRAID improvements".

I can be wrong, but looks like it is most likely to hang about 8Gb...

Kernel built with:
options	SMP
options	apic
options	SCHED_4BSD
options	PREEMPTION
options	ADAPTIVE_GIANT



>How-To-Repeat:


dd if=/dev/amrd0 of=/dev/null bs=1m skip=8000



>Fix:


use amr(4) from 6.0-RELEASE


>Release-Note:
>Audit-Trail:
>Unformatted: