Re: libata total system lockup fix

[Tejun Heo <htejun@gmail.com>]

Mark Lord wrote:
> Tejun Heo wrote:
> 
>>
>>  I've been trying to reproduce your lockup here, but haven't succeeded 
>> yet.  I'm currently doing multiple "while true; do cat /dev/sr0; 
>> done", bonnie, raw random IOs (latter two are to give some randomness 
>> to test condition).
> 
> 
> Gotta trigger the eh code to get lockups, and hard disks are
> so reliable by themselves that it just ain't gonna happen
> very often that way.

  Yeap, the sr0 is my SATA DVD+-RW/DL drive, and as no media is present, 
each cat results in EH handling leading to No medium found error.

> 
> My notebook has a DVD+-RW/DL drive, which the desktop (KDE) polls
> every second or so -- generates a libata error every time it does
> that with no disk in the drive.  But hours or days can go by before
> this produces the race that locks things up (and it NEVER locks up
> if I keep a disc in the drive).

  Okay, I'll keep my test running for longer.

> 
> However, I have had the machine lock up solid during suspend/resume (RAM)
> at least once in the past couple of days --> perhaps a command timeout
> on accessing the disk on resume (or suspend?) is aggrievating
> the situation.  No problems with the large "broken" fix,
> but the one-liner was just giving me too much grief.

  Hmmm, if the lockup only occurs w/ suspend/resume w/ one-liner.  The 
lockup could be a different problem.  I'll try to dig deeper.

> The laptop & I are off for a road trip for the next seven days or so,
> and it will be in constant daily use for presentations and stuff.
> So, no risky testing over the next week, sorry.

  Dang. :-p

-- 
tejun