Re: kern/38035: repeatable kernel lock spinout

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

The following reply was made to PR kern/38035; it has been noted by GNATS.

From: yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)
To: gnats-bugs%NetBSD.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, 
netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/38035: repeatable kernel lock spinout
Date: Fri, 15 Feb 2008 18:58:25 +0900 (JST)

 > Kernel lock error: _kernel_lock: spinout
 > 
 > with a backtrace of:
 > 
 > _kernel_lock()
 > _intr_biglock_wrapper()
 > DDB lost frame ... trying...
 > Xintr_ioapic_level11
 > --interrupt frame--
 > _kernel_lock
 > biodone2
 > biointr
 > softint_dispatch
 > ...
 
 a backtrace of the interrupted lwp might be interesting.
 
 > other cpu:
 > __cpu_simple_lock()
 
 i guess the interrupted lwp is holding this lock.
 if so, making it a spin mutex with IPL_VM (or an adaptive mutex if its safe)
 is a usual solution.
 
 > rf_DiskReadFuncForTheads()
 
 rf_DiskReadFuncForThreads ?
 
 YAMAMOTO Takashi
 
 > FireNode()
 > FireNodeList()
 > rf_FinishNode()
 > rf_NullNodeFunc()
 > FireNode()
 > rf_DispatchDAG()
 > rf_VerifyParityRAID1()
 > rf_RewriteParity()
 > rf_RewriteParityThread()
 > 
 > >How-To-Repeat:
 > on my machine, rebooting with dirty raid parity does it
 > 
 > >Fix:
 > n/a