Currently a device does not belong to any of the numa nodes (dev->numa_node is NUMA_NO_NODE) when the node id is neither specified by fw nor by virtual device layer and the device has no parent device.
According to discussion in [1]: Even if a device's numa node is not specified, the device really does belong to a node. This patch sets the device node to node 0 in device_add() if the device's node id is not specified and it either has no parent device, or the parent device also does not have a valid node id. [1] https://lkml.org/lkml/2019/9/2/466 Signed-off-by: Yunsheng Lin <linyunsh...@huawei.com> --- Changelog RFC -> v1: 1. Drop log error message and use a "if" instead of "? :". 2. Drop the RFC tag. --- drivers/base/core.c | 10 +++++++--- include/linux/numa.h | 2 ++ 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 1669d41..f79ad20 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2107,9 +2107,13 @@ int device_add(struct device *dev) if (kobj) dev->kobj.parent = kobj; - /* use parent numa_node */ - if (parent && (dev_to_node(dev) == NUMA_NO_NODE)) - set_dev_node(dev, dev_to_node(parent)); + /* use parent numa_node or default node 0 */ + if (!numa_node_valid(dev_to_node(dev))) { + if (parent && numa_node_valid(dev_to_node(parent))) + set_dev_node(dev, dev_to_node(parent)); + else + set_dev_node(dev, 0); + } /* first, register with generic layer. */ /* we require the name to be set before, and pass NULL */ diff --git a/include/linux/numa.h b/include/linux/numa.h index 110b0e5..eccc757 100644 --- a/include/linux/numa.h +++ b/include/linux/numa.h @@ -13,4 +13,6 @@ #define NUMA_NO_NODE (-1) +#define numa_node_valid(node) ((unsigned int)(node) < nr_node_ids) + #endif /* _LINUX_NUMA_H */ -- 2.8.1
