acpi: Fix CPU hot removal problem
PATCH v2 1/1 acpi: Fix CPU hot removal problem
We run Linux as a guest in Xen environment. When used xen tools (xm vcpu-set <n>) to hot add and remove vcpu to and from the guest,
we encountered the failure on vcpu removal. We found the reason is
that it didn't go to really remove cpu in the cpu removal code path.
This patch adds acpi_bus_trim in acpi_process_hotplug_notify to fix this issue. With this patch, it works fine for us.
--- drivers/acpi/processor_driver.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)
drivers/acpi/processor_driver.c +5 -0
@@ -678,7 +678,11 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,return ; } +if (acpi_bus_trim (device,1 )) { + printk(KERN_ERR PREFIX + "Removing device failed\n"); +return ; + }break ;default : ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Signature · 1 line
1.7.6
Quoted 29 lines · canquan.shen
We run Linux as a guest in Xen environment. When used xen tools (xm vcpu-set <n>) to hot add and remove vcpu to and from the guest, we encountered the failure on vcpu removal. We found the reason is that it didn't go to really remove cpu in the cpu removal code path.
This patch adds
acpi_bus_triminacpi_process_hotplug_notifyto fix this issue. With this patch, it works fine for us.Signed-off-by Canquan Shen <[email protected]>---
drivers/acpi/processor_driver.c| 5 +++++1 files changed, 5 insertions(+), 0 deletions(-)drivers/acpi/processor_driver.c +5
-0@@ -678,7 +678,11 @@ static void acpi_processor_hotplug_notify(acpi_handle handle, return; } +if (acpi_bus_trim (device,1 )) { + printk(KERN_ERR PREFIX + "Removing device failed\n"); +return ; + }break ;
Quoted 2 lines
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Hi Len,
I just see your email in linux-kernel maillist and known that your
kernel.org email is kaput, so I resend this email to your intel email address.
Thanks,
- Canquan Shen
Quoted 25 lines · canquan.shen
Quoted 24 lines · canquan.shen
We run Linux as a guest in Xen environment. When used xen tools (xm vcpu-set <n>) to hot add and remove vcpu to and from the guest, we encountered the failure on vcpu removal. We found the reason is that it didn't go to really remove cpu in the cpu removal code path.
This patch adds
acpi_bus_triminacpi_process_hotplug_notifyto fix this issue. With this patch, it works fine for us.Signed-off-by Canquan Shen <[email protected]>---
drivers/acpi/processor_driver.c| 5 +++++1 files changed, 5 insertions(+), 0 deletions(-)drivers/acpi/processor_driver.c +0
-0@@ -678,7 +678,11 @@ static void acpi_processor_hotplug_notify(acpi_handle handle, return; }
Quoted 8 lines
Quoted 8 lines
drivers/acpi/processor_driver.c +5
-0+if (acpi_bus_trim (device,1 )) { + printk(KERN_ERR PREFIX + "Removing device failed\n"); +return ; + }break ;default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
I think this patch is OK. One nit is that kernel printks should never be constant strings. There's almost always more information that's useful in debugging. This error should at least tell us which driver is involved, and preferably which specific device (though we have to be careful in case the device struct is freed by acpi_bus_trim()).
Bjorn