Bug 14345

Summary:	very long pause with clocksource=tsc after checking the root fs
Product:	Sisyphus	Reporter:	Ivan Zakharyaschev <imz>
Component:	SysVinit	Assignee:	Dmitry V. Levin <ldv>
Status:	NEW ---	QA Contact:	qa-sisyphus
Severity:	minor
Priority:	P2	CC:	mike
Version:	unstable
Hardware:	all
OS:	Linux

Description Ivan Zakharyaschev 2008-02-06 18:55:35 MSK

SysVinit-2.86-alt1

I discovered this while experimenting because of the bug with system clock
https://bugzilla.altlinux.org/show_bug.cgi?id=14258 . 

The described effect appears together with a similar effect:
https://bugzilla.altlinux.org/show_bug.cgi?id=14343 .

$ rpm -q kernel-image-wks-smp-2.6.18-alt1 -i
Name        : kernel-image-wks-smp         Relocations: (not relocateable)
Version     : 2.6.18                            Vendor: ALT Linux Team
Release     : alt1                          Build Date: Срд 13 Дек 2006 02:28:15
Install date: Срд 21 Фев 2007 02:43:51      Build Host: bee5.hasher.altlinux.org
Group       : System/Kernel and hardware    Source RPM:
kernel-image-wks-smp-2.6.18-alt1.src.rpm
Size        : 44948311                         License: GPL
Packager    : Konstantin A. Lepikhov <lakostis@altlinux.ru>
<....>
Steps to Reproduce:
1. boot 2.6.24-wks-smp-alt1 with clocksource=tsc
2.
3.
Actual Results:  
After the root fs is mounted read-only (and it is written that it has been
checked), the boot-up sequence pauses for about 40 sec. Only after that the
message like "Remounting the root filesystem read-write" is written.

Expected Results:  
Normally, there is no pause at all at this moment (e.g., on 2.6.24-wks-smp-alt1
with default options).

Comment 1 Ivan Zakharyaschev 2008-02-06 19:33:01 MSK

(In reply to comment #0)
> After the root fs is mounted read-only (and it is written that it has been
> checked),

I meant after it was checked while being read-only; before remounting it in
read-write mode.

Comment 2 Ivan Zakharyaschev 2008-02-07 05:07:02 MSK

I also experienced this delay on 2.6.24-std-def-alt2 with clocksource=tsc.

(With this option, 2.6.24-std-def-alt2 also has the bad behavior of the system
clock: https://bugzilla.altlinux.org/show_bug.cgi?id=14258#c18 ).


Perhaps, this is not a bug and an expected behavior under this kernel parameter.
But I wonder why other programs work without delays then.

Comment 3 Michael Shigorin 2010-08-25 08:48:10 MSD

Ivan, is it still there?