| Message ID | 20250401092716.537512-1-osalvador@suse.de (mailing list archive) |
|---|---|
| Headers | show |
| Series | Implement numa node notifier | expand |
On 4/1/25 11:27, Oscar Salvador wrote: > Memory notifier is a tool that allow consumers to get notified whenever > memory gets onlined or offlined in the system. > Currently, there are 10 consumers of that, but 5 out of those 10 consumers > are only interested in getting notifications when a numa node has changed its > state. > That means going from memoryless to memory-aware of vice versa. > > Which means that for every {online,offline}_pages operation they get > notified even though the numa node might not have changed its state. > > The first patch implements a numa node notifier that does just that, and have > those consumers register in there, so they get notified only when they are > interested. What if we had two chains: register_node_notifier() register_node_normal_notifier() I think they could have shared the state #defines and struct node_notify would have just one nid and be always >= 0. Or would it add too much extra boilerplate and only slab cares? > The second patch replaces 'status_change_normal{_normal}' fields within > memory_notify with a 'nid', as that is only what we need for memory > notifer and update the only user of it (page_ext). > > Consumers that are only interested in numa node states change are: > > - memory-tier > - slub > - cpuset > - hmat > - cxl > > > Oscar Salvador (2): > mm,memory_hotplug: Implement numa node notifier > mm,memory_hotplug: Replace status_change_nid parameter in > memory_notify > > drivers/acpi/numa/hmat.c | 6 +-- > drivers/base/node.c | 19 +++++++++ > drivers/cxl/core/region.c | 14 +++---- > drivers/cxl/cxl.h | 4 +- > include/linux/memory.h | 37 ++++++++++++++++++ > kernel/cgroup/cpuset.c | 2 +- > mm/memory-tiers.c | 8 ++-- > mm/memory_hotplug.c | 82 +++++++++++++++++++++++++++++---------- > mm/page_ext.c | 12 +----- > mm/slub.c | 22 +++++------ > 10 files changed, 146 insertions(+), 60 deletions(-) >
On Wed, Apr 02, 2025 at 06:06:51PM +0200, Vlastimil Babka wrote: > What if we had two chains: > > register_node_notifier() > register_node_normal_notifier() > > I think they could have shared the state #defines and struct node_notify > would have just one nid and be always >= 0. > > Or would it add too much extra boilerplate and only slab cares? We could indeed go on that direction to try to decouple status_change_nid from status_change_nid_normal. Although as you said, slub is the only user of status_change_nid_normal for the time beign, so I am not sure of adding a second chain for only one user. Might look cleaner though, and the advantatge is that slub would not get notified for nodes adquiring only ZONE_MOVABLE. Let us see what David thinks about it. thanks for the suggestion ;-)
Memory notifier is a tool that allow consumers to get notified whenever memory gets onlined or offlined in the system. Currently, there are 10 consumers of that, but 5 out of those 10 consumers are only interested in getting notifications when a numa node has changed its state. That means going from memoryless to memory-aware of vice versa. Which means that for every {online,offline}_pages operation they get notified even though the numa node might not have changed its state. The first patch implements a numa node notifier that does just that, and have those consumers register in there, so they get notified only when they are interested. The second patch replaces 'status_change_normal{_normal}' fields within memory_notify with a 'nid', as that is only what we need for memory notifer and update the only user of it (page_ext). Consumers that are only interested in numa node states change are: - memory-tier - slub - cpuset - hmat - cxl Oscar Salvador (2): mm,memory_hotplug: Implement numa node notifier mm,memory_hotplug: Replace status_change_nid parameter in memory_notify drivers/acpi/numa/hmat.c | 6 +-- drivers/base/node.c | 19 +++++++++ drivers/cxl/core/region.c | 14 +++---- drivers/cxl/cxl.h | 4 +- include/linux/memory.h | 37 ++++++++++++++++++ kernel/cgroup/cpuset.c | 2 +- mm/memory-tiers.c | 8 ++-- mm/memory_hotplug.c | 82 +++++++++++++++++++++++++++++---------- mm/page_ext.c | 12 +----- mm/slub.c | 22 +++++------ 10 files changed, 146 insertions(+), 60 deletions(-)