Author: cperciva
Date: Mon Nov 29 06:50:30 2010
New Revision: 216041
URL: http://svn.freebsd.org/changeset/base/216041
Log:
Fix bug introduced by r194784: Under XEN, the page(s) allocated to dpcpu
for CPU #0 weren't being properly reserved. Under VM pressure this would
cause problems when the dpcpu structures were overwritten by arbitrary
data; the most common symptom was a panic when netisr attempted to lock a
mutex.
For some reason the XEN code keeps track of the start of available memory
in the variables 'first', 'physfree', and 'init_first'; as far as I can
tell, we always have first == physfree == init_first * PAGE_SIZE. The
earlier commit adjusted 'first' (which, on !XEN, is the only variable
which tracks this value) but not the other two variables.
Exercise for reader: Eliminate two of these three variables.
Modified:
head/sys/i386/i386/machdep.c
Modified: head/sys/i386/i386/machdep.c
==============================================================================
--- head/sys/i386/i386/machdep.c Mon Nov 29 05:50:20 2010
(r216040)
+++ head/sys/i386/i386/machdep.c Mon Nov 29 06:50:30 2010
(r216041)
@@ -2576,6 +2576,8 @@ init386(first)
pmap_kenter(pa + KERNBASE, pa);
dpcpu_init((void *)(first + KERNBASE), 0);
first += DPCPU_SIZE;
+ physfree += DPCPU_SIZE;
+ init_first += DPCPU_SIZE / PAGE_SIZE;
PCPU_SET(prvspace, pc);
PCPU_SET(curthread, &thread0);
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
