| Message ID | 20221116-acpi_hmat_fix-v2-2-3712569be691@intel.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | ACPI: HMAT: fix single-initiator target registrations | expand |
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: <stable@vger.kernel.org> > Cc: Rafael J. Wysocki <rafael@kernel.org> > Cc: Liu Shixin <liushixin2@huawei.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Reported-by: Chris Piper <chris.d.piper@intel.com> > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
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: <stable@vger.kernel.org> > Cc: Rafael J. Wysocki <rafael@kernel.org> > Cc: Liu Shixin <liushixin2@huawei.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Reported-by: Chris Piper <chris.d.piper@intel.com> > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > 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(&initiators)) > + return -ENXIO; > + > + list_for_each_entry(initiator, &initiators, 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, &initiators, initiator_cmp); > + list_sort(NULL, &initiators, 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, &initiators, initiator_cmp); > + if (initiators_to_nodemask(p_nodes) < 0) > + return; > + > for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) { > loc = localities_types[i]; > if (!loc) >
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(&initiators)) + return -ENXIO; + + list_for_each_entry(initiator, &initiators, 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, &initiators, initiator_cmp); + list_sort(NULL, &initiators, 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, &initiators, initiator_cmp); + if (initiators_to_nodemask(p_nodes) < 0) + return; + for (i = WRITE_LATENCY; i <= READ_BANDWIDTH; i++) { loc = localities_types[i]; if (!loc)
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: <stable@vger.kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Chris Piper <chris.d.piper@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> --- drivers/acpi/numa/hmat.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-)