Bug 160019
Summary: | Full-duplex Gigabit can not reach gigabit at both RX/TX same time | ||
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Product: | Red Hat Enterprise Linux 3 | Reporter: | Robinson Tiemuqinke <hahaha_30k> |
Component: | kernel | Assignee: | John W. Linville <linville> |
Status: | CLOSED WONTFIX | QA Contact: | Brian Brock <bbrock> |
Severity: | medium | Docs Contact: | |
Priority: | medium | ||
Version: | 3.0 | CC: | davem, petrides |
Target Milestone: | --- | ||
Target Release: | --- | ||
Hardware: | i686 | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | Bug Fix | |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2005-08-03 16:11:22 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Robinson Tiemuqinke
2005-06-10 01:33:33 UTC
*** Bug 160020 has been marked as a duplicate of this bug. *** Not true, the some should not be 220MB/sec. You're forgetting that the opposite direction of the transfer is consumed by ACK packets. So for the single transfer case you have: SENDER --> DATA --> DATA --> DATA --> DATA --> DATA --> RECEIVER SENDER <-- ACK <-- ACK <-- ACK <-- ACK <-- ACK <-- RECEIVER With the case of two transfers going at once you have: Host1 --> DATA --> ACK --> DATA --> ACK --> DATA --> ACK Host2 Host2 <-- ACK <-- DATA <-- ACK <-- DATA <-- ACK <-- DATA Host2 This is not a bug. David Miller, Thanks for you quick reply. But I've also tested the normal 100Mbits/s network cards in full-duplex modes. with two pairs of sending-receiving ttcp on two Redhat Linux hosts. The results are: On each machine, the sending side speed is 12MB/s, receiving speed is also at 12MB/s. totally the SUM is 24MB/s, quite close to the capacity of 200Mbits/s(added sending and receiving sides). The above is quite easy to reproduce, you can use two 100Mbits/s cards, or Gigabit works at 100Mbits/s fFull-duplex mode. The OS can be Redhat Enterprise Linux or Fedora Core, kernel can be 2.4 or 2.6. The results is exactly the same. What NICs are you using (particular in the xw4200)? Are they actually PCI-E? Or are they PCI(-X)? Please attach the output of running "sysreport" to this bug. Thanks! Closed due to inactivity. Please reopen when requested information becomes available. Thanks! |