svn commit: r283262 - stable/10/sys/amd64/amd64
Ed Maste
emaste at FreeBSD.org
Thu May 21 19:40:32 UTC 2015
Author: emaste
Date: Thu May 21 19:40:31 2015
New Revision: 283262
URL: https://svnweb.freebsd.org/changeset/base/283262
Log:
MFC r258431: Disable amd64 boot time memory test by default
The page presence memory test takes a long time on large memory systems
and has little value on contemporary amd64 hardware.
Relnotes: Yes
Reviewed by: jhb, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1544
Modified:
stable/10/sys/amd64/amd64/machdep.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/amd64/amd64/machdep.c
==============================================================================
--- stable/10/sys/amd64/amd64/machdep.c Thu May 21 19:31:10 2015 (r283261)
+++ stable/10/sys/amd64/amd64/machdep.c Thu May 21 19:40:31 2015 (r283262)
@@ -1590,13 +1590,15 @@ getmemsize(caddr_t kmdp, u_int64_t first
Maxmem = atop(physmem_tunable);
/*
- * By default enable the memory test on real hardware, and disable
- * it if we appear to be running in a VM. This avoids touching all
- * pages unnecessarily, which doesn't matter on real hardware but is
- * bad for shared VM hosts. Use a general name so that
- * one could eventually do more with the code than just disable it.
+ * The boot memory test is disabled by default, as it takes a
+ * significant amount of time on large-memory systems, and is
+ * unfriendly to virtual machines as it unnecessarily touches all
+ * pages.
+ *
+ * A general name is used as the code may be extended to support
+ * additional tests beyond the current "page present" test.
*/
- memtest = (vm_guest > VM_GUEST_NO) ? 0 : 1;
+ memtest = 0;
TUNABLE_ULONG_FETCH("hw.memtest.tests", &memtest);
/*
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