| Message ID | 20220422195516.10769-3-jvgediya@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: demotion: Introduce new node state N_DEMOTION_TARGETS | expand |
On Fri, Apr 22, 2022 at 12:55 PM Jagdish Gediya <jvgediya@linux.ibm.com> wrote: > > Some systems(e.g. PowerVM) have DRAM(fast memory) only NUMA node > which are N_MEMORY as well as slow memory(persistent memory) only > NUMA node which are also N_MEMORY. As the current demotion target > finding algorithm works based on N_MEMORY and best distance, it can > choose DRAM only NUMA node as demotion target instead of persistent > memory node on such systems. If DRAM only NUMA node is filled with > demoted pages then at some point new allocations can start falling > to persistent memory, so basically cold pages are in fast memory > (due to demotion) and new pages are in slow memory, this is why > persistent memory nodes should be utilized for demotion and dram node > should be avoided for demotion so that they can be used for new > allocations. > > Add new state N_DEMOTION_TARGETS, node_states[N_DEMOTION_TARGETS] > then can be used to hold the list of nodes which can be used > as demotion targets, later patches in the series builds demotion > targets based on nodes available in node_states[N_DEMOTION_TARGETS]. > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > Signed-off-by: Jagdish Gediya <jvgediya@linux.ibm.com> > --- > drivers/base/node.c | 4 ++++ > include/linux/nodemask.h | 1 + > 2 files changed, 5 insertions(+) > Acked-by: Wei Xu <weixugc@google.com> > diff --git a/drivers/base/node.c b/drivers/base/node.c > index ec8bb24a5a22..6eef22e6413e 100644 > --- a/drivers/base/node.c > +++ b/drivers/base/node.c > @@ -1038,6 +1038,9 @@ static struct node_attr node_state_attr[] = { > [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), > [N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator, > N_GENERIC_INITIATOR), > + [N_DEMOTION_TARGETS] = _NODE_ATTR(demotion_targets, > + N_DEMOTION_TARGETS), > + > }; > > static struct attribute *node_state_attrs[] = { > @@ -1050,6 +1053,7 @@ static struct attribute *node_state_attrs[] = { > &node_state_attr[N_MEMORY].attr.attr, > &node_state_attr[N_CPU].attr.attr, > &node_state_attr[N_GENERIC_INITIATOR].attr.attr, > + &node_state_attr[N_DEMOTION_TARGETS].attr.attr, > NULL > }; > > diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h > index 567c3ddba2c4..17844300fd57 100644 > --- a/include/linux/nodemask.h > +++ b/include/linux/nodemask.h > @@ -400,6 +400,7 @@ enum node_states { > N_MEMORY, /* The node has memory(regular, high, movable) */ > N_CPU, /* The node has one or more cpus */ > N_GENERIC_INITIATOR, /* The node has one or more Generic Initiators */ > + N_DEMOTION_TARGETS, /* Nodes that should be considered as demotion targets */ > NR_NODE_STATES > }; > > -- > 2.35.1 >
diff --git a/drivers/base/node.c b/drivers/base/node.c index ec8bb24a5a22..6eef22e6413e 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -1038,6 +1038,9 @@ static struct node_attr node_state_attr[] = { [N_CPU] = _NODE_ATTR(has_cpu, N_CPU), [N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator, N_GENERIC_INITIATOR), + [N_DEMOTION_TARGETS] = _NODE_ATTR(demotion_targets, + N_DEMOTION_TARGETS), + }; static struct attribute *node_state_attrs[] = { @@ -1050,6 +1053,7 @@ static struct attribute *node_state_attrs[] = { &node_state_attr[N_MEMORY].attr.attr, &node_state_attr[N_CPU].attr.attr, &node_state_attr[N_GENERIC_INITIATOR].attr.attr, + &node_state_attr[N_DEMOTION_TARGETS].attr.attr, NULL }; diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h index 567c3ddba2c4..17844300fd57 100644 --- a/include/linux/nodemask.h +++ b/include/linux/nodemask.h @@ -400,6 +400,7 @@ enum node_states { N_MEMORY, /* The node has memory(regular, high, movable) */ N_CPU, /* The node has one or more cpus */ N_GENERIC_INITIATOR, /* The node has one or more Generic Initiators */ + N_DEMOTION_TARGETS, /* Nodes that should be considered as demotion targets */ NR_NODE_STATES };