From: Kenji Kaneshige <kaneshige.kenji@soft.fujitsu.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-acpi@vger.kernel.org
Cc: Len Brown <len.brown@intel.com>, Andrew Morton <akpm@osdl.org>
Subject: [PATCH][BUG] fix bug in ACPI based CPU hotplug
Date: Wed, 08 Mar 2006 16:26:27 +0900 [thread overview]
Message-ID: <440E8723.7030008@soft.fujitsu.com> (raw)
Hi,
I found a bug in ACPI based CPU hotplug code. Because of this bug,
ACPI based CPU hotplug will always fail if NR_CPUS is equal to or
more than 255.
Thanks,
Kenji Kaneshige
This patch fixes a serious bug in ACPI based CPU hotplug code. Because
of this bug, ACPI based CPU hotplug will always fail if NR_CPUS is
equal to or more than 255.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Motoyuki Itoh <motoyuki@soft.fujitsu.com>
---
drivers/acpi/processor_core.c | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)
Index: linux-2.6.16-rc5-mm2/drivers/acpi/processor_core.c
===================================================================
--- linux-2.6.16-rc5-mm2.orig/drivers/acpi/processor_core.c 2006-03-07 13:42:20.000000000 +0900
+++ linux-2.6.16-rc5-mm2/drivers/acpi/processor_core.c 2006-03-08 14:03:58.000000000 +0900
@@ -382,7 +382,7 @@
/* Use the acpiid in MADT to map cpus in case of SMP */
#ifndef CONFIG_SMP
-#define convert_acpiid_to_cpu(acpi_id) (0xff)
+#define convert_acpiid_to_cpu(acpi_id) (-1)
#else
#ifdef CONFIG_IA64
@@ -395,7 +395,7 @@
#define ARCH_BAD_APICID (0xff)
#endif
-static u8 convert_acpiid_to_cpu(u8 acpi_id)
+static int convert_acpiid_to_cpu(u8 acpi_id)
{
u16 apic_id;
int i;
@@ -421,7 +421,7 @@
acpi_status status = 0;
union acpi_object object = { 0 };
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
- u8 cpu_index;
+ int cpu_index;
static int cpu0_initialized;
ACPI_FUNCTION_TRACE("acpi_processor_get_info");
@@ -466,8 +466,7 @@
cpu_index = convert_acpiid_to_cpu(pr->acpi_id);
/* Handle UP system running SMP kernel, with no LAPIC in MADT */
- if (!cpu0_initialized && (cpu_index == 0xff) &&
- (num_online_cpus() == 1)) {
+ if (!cpu0_initialized && (cpu_index < 0) && (num_online_cpus() == 1)) {
cpu_index = 0;
}
@@ -480,7 +479,7 @@
* less than the max # of CPUs. They should be ignored _iff
* they are physically not present.
*/
- if (cpu_index >= NR_CPUS) {
+ if (cpu_index < 0) {
if (ACPI_FAILURE
(acpi_processor_hotadd_init(pr->handle, &pr->id))) {
ACPI_ERROR((AE_INFO,
next reply other threads:[~2006-03-08 7:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-08 7:26 Kenji Kaneshige [this message]
2006-03-08 7:35 ` [PATCH][BUG] fix bug in ACPI based CPU hotplug Andrew Morton
2006-03-08 8:10 ` Kenji Kaneshige
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