PR/38989 CVS commit: src/sys/uvm

[Matthias Drochner <drochner%netbsd.org@localhost>]

The following reply was made to PR port-i386/38989; it has been noted by GNATS.

From: Matthias Drochner <drochner%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/38989 CVS commit: src/sys/uvm
Date: Thu, 26 Feb 2009 18:18:14 +0000 (UTC)

 Module Name:   src
 Committed By:  drochner
 Date:          Thu Feb 26 18:18:14 UTC 2009
 
 Modified Files:
        src/sys/uvm: uvm_page.c
 
 Log Message:
 -fix two conditions where PQ_FREE was still/already set while the page
  was not anymore/yet on the freelist and uvm_fpageqlock was not held
 -clear PQ_FREE while the page is in the works of pageidlezero
 This avoids that the DMA memory allocator (pglistalloc) grabs a page
 which is not on the freelist, leading to a diagnostic panic (with DEBUG)
 or freelist corruption. (mostly on X server activation after a VT
 switch or suspend/resume because this can allocate megabytes of AGP
 memory)
 This might fix PR port-i386/38989 by Alan Barrett (in case this was
 a multiprocessor).
 
 
 To generate a diff of this commit:
 cvs rdiff -r1.142 -r1.143 src/sys/uvm/uvm_page.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.