Re: [PATCH v2 2/2] ACPI: HMAT: Fix initiator registration for single-initiator systems
On 11/17/2022 12:37 AM, Vishal Verma wrote:
In a system with a single initiator node, and one or more memory-only
'target' nodes, the memory-only node(s) would fail to register their
initiator node correctly. i.e. in sysfs:
# ls /sys/devices/system/node/node0/access0/targets/
node0
Where as the correct behavior should be:
# ls /sys/devices/system/node/node0/access0/targets/
node0 node1
This happened because hmat_register_target_initiators() uses list_sort()
to sort the initiator list, but the sort comparision function
(initiator_cmp()) is overloaded to also set the node mask's bits.
In a system with a single initiator, the list is singular, and list_sort
elides the comparision helper call. Thus the node mask never gets set,
and the subsequent search for the best initiator comes up empty.
Add a new helper to consume the sorted initiator list, and generate the
nodemask, decoupling it from the overloaded initiator_cmp() comparision
callback. This prevents the singular list corner case naturally, and
makes the code easier to follow as well.
Cc:
Cc: Rafael J. Wysocki
Cc: Liu Shixin
Cc: Dan Williams
Cc: Kirill A. Shutemov
Reported-by: Chris Piper
Signed-off-by: Vishal Verma
Acked-by: Rafael J. Wysocki
---
drivers/acpi/numa/hmat.c | 26 --
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index 144a84f429ed..6cceca64a6bc 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -562,17 +562,26 @@ static int initiator_cmp(void *priv, const struct
list_head *a,
{
struct memory_initiator *ia;
struct memory_initiator *ib;
- unsigned long *p_nodes = priv;
ia = list_entry(a, struct memory_initiator, node);
ib = list_entry(b, struct memory_initiator, node);
- set_bit(ia->processor_pxm, p_nodes);
- set_bit(ib->processor_pxm, p_nodes);
-
return ia->processor_pxm - ib->processor_pxm;
}
+static int initiators_to_nodemask(unsigned long *p_nodes)
+{
+ struct memory_initiator *initiator;
+
+ if (list_empty())
+ return -ENXIO;
+
+ list_for_each_entry(initiator, , node)
+ set_bit(initiator->processor_pxm, p_nodes);
+
+ return 0;
+}
+
static void hmat_register_target_initiators(struct memory_target *target)
{
static DECLARE_BITMAP(p_nodes, MAX_NUMNODES);
@@ -609,7 +618,10 @@ static void hmat_register_target_initiators(struct
memory_target *target)
* initiators.
*/
bitmap_zero(p_nodes, MAX_NUMNODES);
- list_sort(p_nodes, , initiator_cmp);
+ list_sort(NULL, , initiator_cmp);
+ if (initiators_to_nodemask(p_nodes) < 0)
+ return;
+
if (!access0done) {
for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) {
loc = localities_types[i];
@@ -643,7 +655,9 @@ static void hmat_register_target_initiators(struct
memory_target *target)
/* Access 1 ignores Generic Initiators */
bitmap_zero(p_nodes, MAX_NUMNODES);
- list_sort(p_nodes, , initiator_cmp);
+ if (initiators_to_nodemask(p_nodes) < 0)
+ return;
+
for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) {
loc = localities_types[i];
if (!loc)
Re: [PATCH v2 2/2] ACPI: HMAT: Fix initiator registration for single-initiator systems
On Wed, Nov 16, 2022 at 04:37:37PM -0700, Vishal Verma wrote: > In a system with a single initiator node, and one or more memory-only > 'target' nodes, the memory-only node(s) would fail to register their > initiator node correctly. i.e. in sysfs: > > # ls /sys/devices/system/node/node0/access0/targets/ > node0 > > Where as the correct behavior should be: > > # ls /sys/devices/system/node/node0/access0/targets/ > node0 node1 > > This happened because hmat_register_target_initiators() uses list_sort() > to sort the initiator list, but the sort comparision function > (initiator_cmp()) is overloaded to also set the node mask's bits. > > In a system with a single initiator, the list is singular, and list_sort > elides the comparision helper call. Thus the node mask never gets set, > and the subsequent search for the best initiator comes up empty. > > Add a new helper to consume the sorted initiator list, and generate the > nodemask, decoupling it from the overloaded initiator_cmp() comparision > callback. This prevents the singular list corner case naturally, and > makes the code easier to follow as well. > > Cc: > Cc: Rafael J. Wysocki > Cc: Liu Shixin > Cc: Dan Williams > Cc: Kirill A. Shutemov > Reported-by: Chris Piper > Signed-off-by: Vishal Verma Acked-by: Kirill A. Shutemov -- Kiryl Shutsemau / Kirill A. Shutemov
[PATCH v2 2/2] ACPI: HMAT: Fix initiator registration for single-initiator systems
In a system with a single initiator node, and one or more memory-only
'target' nodes, the memory-only node(s) would fail to register their
initiator node correctly. i.e. in sysfs:
# ls /sys/devices/system/node/node0/access0/targets/
node0
Where as the correct behavior should be:
# ls /sys/devices/system/node/node0/access0/targets/
node0 node1
This happened because hmat_register_target_initiators() uses list_sort()
to sort the initiator list, but the sort comparision function
(initiator_cmp()) is overloaded to also set the node mask's bits.
In a system with a single initiator, the list is singular, and list_sort
elides the comparision helper call. Thus the node mask never gets set,
and the subsequent search for the best initiator comes up empty.
Add a new helper to consume the sorted initiator list, and generate the
nodemask, decoupling it from the overloaded initiator_cmp() comparision
callback. This prevents the singular list corner case naturally, and
makes the code easier to follow as well.
Cc:
Cc: Rafael J. Wysocki
Cc: Liu Shixin
Cc: Dan Williams
Cc: Kirill A. Shutemov
Reported-by: Chris Piper
Signed-off-by: Vishal Verma
---
drivers/acpi/numa/hmat.c | 26 --
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index 144a84f429ed..6cceca64a6bc 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -562,17 +562,26 @@ static int initiator_cmp(void *priv, const struct
list_head *a,
{
struct memory_initiator *ia;
struct memory_initiator *ib;
- unsigned long *p_nodes = priv;
ia = list_entry(a, struct memory_initiator, node);
ib = list_entry(b, struct memory_initiator, node);
- set_bit(ia->processor_pxm, p_nodes);
- set_bit(ib->processor_pxm, p_nodes);
-
return ia->processor_pxm - ib->processor_pxm;
}
+static int initiators_to_nodemask(unsigned long *p_nodes)
+{
+ struct memory_initiator *initiator;
+
+ if (list_empty())
+ return -ENXIO;
+
+ list_for_each_entry(initiator, , node)
+ set_bit(initiator->processor_pxm, p_nodes);
+
+ return 0;
+}
+
static void hmat_register_target_initiators(struct memory_target *target)
{
static DECLARE_BITMAP(p_nodes, MAX_NUMNODES);
@@ -609,7 +618,10 @@ static void hmat_register_target_initiators(struct
memory_target *target)
* initiators.
*/
bitmap_zero(p_nodes, MAX_NUMNODES);
- list_sort(p_nodes, , initiator_cmp);
+ list_sort(NULL, , initiator_cmp);
+ if (initiators_to_nodemask(p_nodes) < 0)
+ return;
+
if (!access0done) {
for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) {
loc = localities_types[i];
@@ -643,7 +655,9 @@ static void hmat_register_target_initiators(struct
memory_target *target)
/* Access 1 ignores Generic Initiators */
bitmap_zero(p_nodes, MAX_NUMNODES);
- list_sort(p_nodes, , initiator_cmp);
+ if (initiators_to_nodemask(p_nodes) < 0)
+ return;
+
for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) {
loc = localities_types[i];
if (!loc)
--
2.38.1
