Bug 53914

Summary: (IRQ Routing) SMP-kernel speeds up system clock under network load
Product: [Retired] Red Hat Linux Reporter: Joachim Frieben <jfrieben>
Component: kernelAssignee: Arjan van de Ven <arjanv>
Status: CLOSED CURRENTRELEASE QA Contact: Brock Organ <borgan>
Severity: high Docs Contact:
Priority: medium    
Version: 9CC: alan
Target Milestone: ---   
Target Release: ---   
Hardware: i686   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2003-12-17 03:25:15 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Description Flags
Actual output of the command 'lspci -vv' none

Description Joachim Frieben 2001-09-21 15:14:46 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv: Gecko/20010901

Description of problem:
The current SMP-kernel speeds up the system clock when data is transferred
via LAN. This is the case as much for incoming as for ougoing data. Using
the ordinary non-SMP-kernel makes this behaviour disappear. The
acceleration factor is about 4 for up-/downloading entire blocks of data
via FTP, and goes up to about 30 (!) when for instance the command 'ls -R
/' is executed on the remote computer, and the output is displayed on the
local host. This behaviour is independent of X and occurs already in a
simple text console at runlevel 3. Furthermore, it does not depend on the
type of connection (TELNET vs SSH).

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Boot system into SMP mode
2. Login in to a remote computer via TELNET/SSH
3. Type 'ls -R /'

Actual Results:  The system clock runs forward in time like crazy!

Expected Results:  System clock keeps running at regular speed

Additional info:

The current system is an INTEL PR440FX based Dual Pentium Pro workstation
with 512 MB of system memory and an integrated INTEL EtherExpress Pro 100B
10/100 MBit/s network adapter.

Comment 1 Arjan van de Ven 2001-09-21 15:23:58 UTC

Could you attach the ouput of "lspci -vv" to this bug ?


Comment 2 Joachim Frieben 2001-09-22 09:02:24 UTC
Created attachment 32398 [details]
Actual output of the command 'lspci -vv'

Comment 3 Alan Cox 2003-06-07 17:56:01 UTC
Is this still the case with the newer kernels. It should be resolved nowdays
(including with the later errata kernels)