Bug 5062

Summary:	kernel preemption breaks in several ways
Product:	Process Management	Reporter:	Sanjoy Mahajan (sanjoy)
Component:	Preemption	Assignee:	Ingo Molnar (mingo)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	linux, mingo, protasnb
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.6.13-rc6	Subsystem:
Regression:	---	Bisected commit-id:
Bug Depends on:	5008, 5037, 5061
Bug Blocks:

Description Sanjoy Mahajan 2005-08-14 00:24:21 UTC

Distribution: Debian testing
Hardware Environment: TP 600X
Software Environment: 
Problem Description: I get the following errors/problems only with pre-emption
enabled in the kernel:

1. pcmcia 'unable to remove socket power" errors (Bug #5061).  Happens if full
preemption is enabled ('low-latency desktop' as preemption model + PREEMPT_BKL),
but not with mild preemption ('voluntary kernel preemption').

2. S3 hangs upon going to sleep (Bug #5037).  It happens regularly with full
pre-emption, not with 'no forced preemption', and probably not with mild
preemption (haven't been running that kernel for long enough to be sure).

3. errors like "os_wait_semaphore     : Failed to acquire" (Bug #5008).  Happens
with full or mild preemption, but not with voluntary preemption.

Steps to reproduce:

Comment 1 Sanjoy Mahajan 2005-08-15 07:29:29 UTC

> 3. errors like "os_wait_semaphore     : Failed to acquire" (Bug #5008). 
Happens > with full or mild preemption, but not with voluntary preemption.

I meant 'but not with no pre-emption'.

Comment 2 Dominik Brodowski 2006-01-10 09:36:13 UTC

What's the status of this bug? Is (at least) part 1 of it resolved?

Comment 3 Sanjoy Mahajan 2006-01-10 11:06:59 UTC

> 3. errors like "os_wait_semaphore     : Failed to acquire" (Bug  #5008). 

This part still happens with 2.6.15 (just started running it) with
'voluntary kernel preemption'.

> 2. S3 hangs upon going to sleep (Bug #5037).

With 2.6.15, I haven't seen this one using voluntary preemption, but I
haven't tried full preemption ('low-latency desktop') yet.

> 1. pcmcia 'unable to remove socket power" errors (Bug #5061). 

Also with 2.6.15, I haven't seen this one with voluntary preemption
but I need to test full preemption.  Daniel Ritz's patch reduced the
problem a lot with 2.6.13 (I think that's what I was running then)
with full preemption.  At first I thought it had solved it, but then I
it happened one more time.

-Sanjoy

`Never underestimate the evil of which men of power are capable.'
         --Bertrand Russell, _War Crimes in Vietnam_, chapter 1.

Comment 4 Natalie Protasevich 2007-07-06 09:26:52 UTC

Any update on this problem?
Thanks.

Comment 5 Ingo Molnar 2007-11-29 08:24:15 UTC

I'm closing this as fixed (all dependent bugs got closed AFAICS), please re-open it if you can still reproduce it.