Discussion:
[Patch v1] ACPI, x86: fix bug in associating hot-added CPUs with corresponding NUMA node
Jiang Liu
2014-01-20 02:31:54 UTC
Permalink
Current ACPI cpu hotplug driver fails to associate hot-added CPUs with
corresponding NUMA node when doing socket online. The code path to
associate CPU with NUMA node is as below:
acpi_processor_add()
->acpi_processor_get_info()
->acpi_processor_hotadd_init()
->acpi_map_lsapic()
->_acpi_map_lsapic()
->acpi_map_cpu2node()
cpu_subsys_online()
->try_online_node()
->node_set_online()

When doing socket online, a new NUMA node is introduced in addition to
hot-added CPU and memory device. And the new NUMA node is marked as
online when onlining hot-added CPUs through sysfs interface
/sys/devices/system/cpu/cpuxx/online.

On the other hand, acpi_map_cpu2node() will only build the CPU to node
map if corresponding NUMA node is already online, so it always fails
to associate hot-added CPUs with corresponding NUMA node because the
NUMA node is still in offline state.

For the fix, we could safely remove the "node_online(node)" check in
function acpi_map_cpu2node() because it's only called for hot-added CPUs
by acpi_processor_hotadd_init().

Signed-off-by: Jiang Liu <***@linux.intel.com>
---
arch/x86/kernel/acpi/boot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6c0b43b..7625de9 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -614,10 +614,10 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
int nid;

nid = acpi_get_node(handle);
- if (nid == -1 || !node_online(nid))
- return;
- set_apicid_to_node(physid, nid);
- numa_set_node(cpu, nid);
+ if (nid != -1) {
+ set_apicid_to_node(physid, nid);
+ numa_set_node(cpu, nid);
+ }
#endif
}
--
1.7.10.4

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Rafael J. Wysocki
2014-02-05 00:14:54 UTC
Permalink
Post by Jiang Liu
Current ACPI cpu hotplug driver fails to associate hot-added CPUs with
corresponding NUMA node when doing socket online. The code path to
acpi_processor_add()
->acpi_processor_get_info()
->acpi_processor_hotadd_init()
->acpi_map_lsapic()
->_acpi_map_lsapic()
->acpi_map_cpu2node()
cpu_subsys_online()
->try_online_node()
->node_set_online()
When doing socket online, a new NUMA node is introduced in addition to
hot-added CPU and memory device. And the new NUMA node is marked as
online when onlining hot-added CPUs through sysfs interface
/sys/devices/system/cpu/cpuxx/online.
On the other hand, acpi_map_cpu2node() will only build the CPU to node
map if corresponding NUMA node is already online, so it always fails
to associate hot-added CPUs with corresponding NUMA node because the
NUMA node is still in offline state.
For the fix, we could safely remove the "node_online(node)" check in
function acpi_map_cpu2node() because it's only called for hot-added CPUs
by acpi_processor_hotadd_init().
I wonder what the status here is? Did this patch go anywhere?
Post by Jiang Liu
---
arch/x86/kernel/acpi/boot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6c0b43b..7625de9 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -614,10 +614,10 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
int nid;
nid = acpi_get_node(handle);
- if (nid == -1 || !node_online(nid))
- return;
- set_apicid_to_node(physid, nid);
- numa_set_node(cpu, nid);
+ if (nid != -1) {
+ set_apicid_to_node(physid, nid);
+ numa_set_node(cpu, nid);
+ }
#endif
}
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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Jiang Liu
2014-02-07 09:17:45 UTC
Permalink
Post by Rafael J. Wysocki
Post by Jiang Liu
Current ACPI cpu hotplug driver fails to associate hot-added CPUs with
corresponding NUMA node when doing socket online. The code path to
acpi_processor_add()
->acpi_processor_get_info()
->acpi_processor_hotadd_init()
->acpi_map_lsapic()
->_acpi_map_lsapic()
->acpi_map_cpu2node()
cpu_subsys_online()
->try_online_node()
->node_set_online()
When doing socket online, a new NUMA node is introduced in addition to
hot-added CPU and memory device. And the new NUMA node is marked as
online when onlining hot-added CPUs through sysfs interface
/sys/devices/system/cpu/cpuxx/online.
On the other hand, acpi_map_cpu2node() will only build the CPU to node
map if corresponding NUMA node is already online, so it always fails
to associate hot-added CPUs with corresponding NUMA node because the
NUMA node is still in offline state.
For the fix, we could safely remove the "node_online(node)" check in
function acpi_map_cpu2node() because it's only called for hot-added CPUs
by acpi_processor_hotadd_init().
I wonder what the status here is? Did this patch go anywhere?
Hi Rafael,
It's still in review stage, hasn't been accepted by any
maintainer yet.
Thanks!
Gerry
Post by Rafael J. Wysocki
Post by Jiang Liu
---
arch/x86/kernel/acpi/boot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6c0b43b..7625de9 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -614,10 +614,10 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
int nid;
nid = acpi_get_node(handle);
- if (nid == -1 || !node_online(nid))
- return;
- set_apicid_to_node(physid, nid);
- numa_set_node(cpu, nid);
+ if (nid != -1) {
+ set_apicid_to_node(physid, nid);
+ numa_set_node(cpu, nid);
+ }
#endif
}
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Rafael J. Wysocki
2014-02-07 12:03:06 UTC
Permalink
Post by Jiang Liu
Post by Rafael J. Wysocki
Post by Jiang Liu
Current ACPI cpu hotplug driver fails to associate hot-added CPUs with
corresponding NUMA node when doing socket online. The code path to
acpi_processor_add()
->acpi_processor_get_info()
->acpi_processor_hotadd_init()
->acpi_map_lsapic()
->_acpi_map_lsapic()
->acpi_map_cpu2node()
cpu_subsys_online()
->try_online_node()
->node_set_online()
When doing socket online, a new NUMA node is introduced in addition to
hot-added CPU and memory device. And the new NUMA node is marked as
online when onlining hot-added CPUs through sysfs interface
/sys/devices/system/cpu/cpuxx/online.
On the other hand, acpi_map_cpu2node() will only build the CPU to node
map if corresponding NUMA node is already online, so it always fails
to associate hot-added CPUs with corresponding NUMA node because the
NUMA node is still in offline state.
For the fix, we could safely remove the "node_online(node)" check in
function acpi_map_cpu2node() because it's only called for hot-added CPUs
by acpi_processor_hotadd_init().
I wonder what the status here is? Did this patch go anywhere?
Hi Rafael,
It's still in review stage, hasn't been accepted by any
maintainer yet.
OK

Peter, are you fine with the patch below?

Rafael
Post by Jiang Liu
Post by Rafael J. Wysocki
Post by Jiang Liu
---
arch/x86/kernel/acpi/boot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6c0b43b..7625de9 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -614,10 +614,10 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
int nid;
nid = acpi_get_node(handle);
- if (nid == -1 || !node_online(nid))
- return;
- set_apicid_to_node(physid, nid);
- numa_set_node(cpu, nid);
+ if (nid != -1) {
+ set_apicid_to_node(physid, nid);
+ numa_set_node(cpu, nid);
+ }
#endif
}
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
Jiang Liu
2014-02-13 02:32:21 UTC
Permalink
Ping...
Post by Rafael J. Wysocki
Post by Jiang Liu
Post by Rafael J. Wysocki
Post by Jiang Liu
Current ACPI cpu hotplug driver fails to associate hot-added CPUs with
corresponding NUMA node when doing socket online. The code path to
acpi_processor_add()
->acpi_processor_get_info()
->acpi_processor_hotadd_init()
->acpi_map_lsapic()
->_acpi_map_lsapic()
->acpi_map_cpu2node()
cpu_subsys_online()
->try_online_node()
->node_set_online()
When doing socket online, a new NUMA node is introduced in addition to
hot-added CPU and memory device. And the new NUMA node is marked as
online when onlining hot-added CPUs through sysfs interface
/sys/devices/system/cpu/cpuxx/online.
On the other hand, acpi_map_cpu2node() will only build the CPU to node
map if corresponding NUMA node is already online, so it always fails
to associate hot-added CPUs with corresponding NUMA node because the
NUMA node is still in offline state.
For the fix, we could safely remove the "node_online(node)" check in
function acpi_map_cpu2node() because it's only called for hot-added CPUs
by acpi_processor_hotadd_init().
I wonder what the status here is? Did this patch go anywhere?
Hi Rafael,
It's still in review stage, hasn't been accepted by any
maintainer yet.
OK
Peter, are you fine with the patch below?
Rafael
Post by Jiang Liu
Post by Rafael J. Wysocki
Post by Jiang Liu
---
arch/x86/kernel/acpi/boot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6c0b43b..7625de9 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -614,10 +614,10 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
int nid;
nid = acpi_get_node(handle);
- if (nid == -1 || !node_online(nid))
- return;
- set_apicid_to_node(physid, nid);
- numa_set_node(cpu, nid);
+ if (nid != -1) {
+ set_apicid_to_node(physid, nid);
+ numa_set_node(cpu, nid);
+ }
#endif
}
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H. Peter Anvin
2014-02-13 03:37:32 UTC
Permalink
Post by Jiang Liu
Ping...
Sorry, will look at it tomorrow.

-hpa


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