Module Name: src
Committed By: jruoho
Date: Mon Aug 9 05:00:24 UTC 2010
Modified Files:
src/sys/dev/acpi: acpi_cpu_cstate.c
Log Message:
Downgrade the currently supported maximum C-state to C1. There appears to be
timer-related interrupt issues also in C2. With C1 it is guaranteed that
acpicpu(4) will not cause any slowdowns due stalled local APIC timer.
To generate a diff of this commit:
cvs rdiff -u -r1.16 -r1.17 src/sys/dev/acpi/acpi_cpu_cstate.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/acpi/acpi_cpu_cstate.c
diff -u src/sys/dev/acpi/acpi_cpu_cstate.c:1.16 src/sys/dev/acpi/acpi_cpu_cstate.c:1.17
--- src/sys/dev/acpi/acpi_cpu_cstate.c:1.16 Sun Aug 8 18:25:06 2010
+++ src/sys/dev/acpi/acpi_cpu_cstate.c Mon Aug 9 05:00:24 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_cstate.c,v 1.16 2010/08/08 18:25:06 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_cstate.c,v 1.17 2010/08/09 05:00:24 jruoho Exp $ */
/*-
* Copyright (c) 2010 Jukka Ruohonen <[email protected]>
@@ -27,7 +27,7 @@
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_cstate.c,v 1.16 2010/08/08 18:25:06 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_cstate.c,v 1.17 2010/08/09 05:00:24 jruoho Exp $");
#include <sys/param.h>
#include <sys/cpu.h>
@@ -65,13 +65,15 @@
extern struct acpicpu_softc **acpicpu_sc;
/*
- * XXX: The local APIC timer (as well as TSC) is typically
- * stopped in C3. For now, we cannot but disable C3.
+ * XXX: The local APIC timer (as well as TSC) is typically stopped in C3.
+ * For now, we cannot but disable C3. But there appears to be timer-
+ * related interrupt issues also in C2. The only entirely safe option
+ * at the moment is to use C1.
*/
#ifdef ACPICPU_ENABLE_C3
static int cs_state_max = ACPI_STATE_C3;
#else
-static int cs_state_max = ACPI_STATE_C2;
+static int cs_state_max = ACPI_STATE_C1;
#endif
void
