Bug 669300

Summary: Fix shrinking windows with window scaling [rhel-5.6.z]
Product: Red Hat Enterprise Linux 5 Reporter: RHEL Program Management <pm-rhel>
Component: kernelAssignee: Jiri Pirko <jpirko>
Status: CLOSED ERRATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: high Docs Contact:
Priority: urgent    
Version: 5.5CC: dhoward, haliu, hjia, jeder, john.daley, jpirko, jwest, nhorman, pm-eus, rkhan, sgandhar, tao
Target Milestone: rcKeywords: ZStream
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: kernel-2.6.18-238.3.1.el5 Doc Type: Bug Fix
Doc Text:
When selecting a new window, the tcp_select_window() function tried not to shrink the offered window by using the maximum of the remaining offered window size and the newly calculated window size. The newly calculated window size was always a multiple of the window scaling factor, however, the remaining window size was not since it depended on rcv_wup/rcv_nxt. As a result, a window was shrunk when it was scaled down. With this update, aligning the remaining window to the window scaling factor assures a window is no longer shrunk.
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-03-01 20:29:49 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:
Bug Depends On: 627496    
Bug Blocks:    

Description RHEL Program Management 2011-01-13 09:01:17 UTC
This bug has been copied from bug #627496 and has been proposed
to be backported to 5.6 z-stream (EUS).

Comment 3 Jiri Pirko 2011-01-26 07:38:10 UTC
in kernel-2.6.18-238.3.1.el5

linux-2.6-net-tcp-fix-shrinking-windows-with-window-scaling.patch

Comment 6 errata-xmlrpc 2011-03-01 20:29:49 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0303.html

Comment 7 Martin Prpič 2011-07-13 20:18:54 UTC
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
When selecting a new window, the tcp_select_window() function tried not to shrink the offered window by using the maximum of the remaining offered window size and the newly calculated window size. The newly calculated window size was always a multiple of the window scaling factor, however, the remaining window size was not since it depended on rcv_wup/rcv_nxt. As a result, a window was shrunk when it was scaled down. With this update, aligning the remaining window to the window scaling factor assures a window is no longer shrunk.