From: Alexander Duyck <[email protected]> This patch is based off of the pci_call_probe function used to initialize PCI devices. The general idea here is to move the probe call to a location that is local to the memory being initialized. By doing this we can shave significant time off of the total time needed for initialization.
With this patch applied I see a significant reduction in overall init time as without it the init varied between 23 and 37 seconds to initialize a 3GB node. With this patch applied the variance is only between 23 and 26 seconds to initialize each node. I hope to refine this further in the future by combining this logic into the async_schedule_domain code that is already in use. By doing that it would likely make this functionality redundant. Signed-off-by: Alexander Duyck <[email protected]> --- drivers/nvdimm/bus.c | 45 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c index 8aae6dcc839f..5b73953176b1 100644 --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -27,6 +27,7 @@ #include <linux/io.h> #include <linux/mm.h> #include <linux/nd.h> +#include <linux/cpu.h> #include "nd-core.h" #include "nd.h" #include "pfn.h" @@ -90,6 +91,48 @@ static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus) nvdimm_bus_unlock(&nvdimm_bus->dev); } +struct nvdimm_drv_dev { + struct nd_device_driver *nd_drv; + struct device *dev; +}; + +static long __nvdimm_call_probe(void *_nddd) +{ + struct nvdimm_drv_dev *nddd = _nddd; + struct nd_device_driver *nd_drv = nddd->nd_drv; + + return nd_drv->probe(nddd->dev); +} + +static int nvdimm_call_probe(struct nd_device_driver *nd_drv, + struct device *dev) +{ + struct nvdimm_drv_dev nddd = { nd_drv, dev }; + int rc, node, cpu; + + /* + * Execute driver initialization on node where the device is + * attached. This way the driver will be able to access local + * memory instead of having to initialize memory across nodes. + */ + node = dev_to_node(dev); + + cpu_hotplug_disable(); + + if (node < 0 || node >= MAX_NUMNODES || !node_online(node)) + cpu = nr_cpu_ids; + else + cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask); + + if (cpu < nr_cpu_ids) + rc = work_on_cpu(cpu, __nvdimm_call_probe, &nddd); + else + rc = __nvdimm_call_probe(&nddd); + + cpu_hotplug_enable(); + return rc; +} + static int nvdimm_bus_probe(struct device *dev) { struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver); @@ -104,7 +147,7 @@ static int nvdimm_bus_probe(struct device *dev) dev->driver->name, dev_name(dev)); nvdimm_bus_probe_start(nvdimm_bus); - rc = nd_drv->probe(dev); + rc = nvdimm_call_probe(nd_drv, dev); if (rc == 0) nd_region_probe_success(nvdimm_bus, dev); else _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
