This patch set provides functionality that will help to improve the locality of the async_schedule calls used to provide deferred initialization.
This patch set originally started out focused on just the one call to async_schedule_domain in the nvdimm tree that was being used to defer the device_add call however after doing some digging I realized the scope of this was much broader than I had originally planned. As such I went through and reworked the underlying infrastructure down to replacing the queue_work call itself with a function of my own and opted to try and provide a NUMA aware solution that would work for a broader audience. In addition I have added several tweaks and/or clean-ups to the front of the patch set. Patches 1 through 3 address a number of issues that actually were causing the existing async_schedule calls to not show the performance that they could due to either not scaling on a per device basis, or due to issues that could result in a potential race. For example, patch 3 addresses the fact that we were calling async_schedule once per driver instead of once per device, and as a result we would have still ended up with devices being probed on a non-local node without addressing this first. I have also updated the kernel module used to test async driver probing so that it can expose the original issue I was attempting to address. It will fail on a system of asynchronous work either takes longer than it takes to load a single device and a single driver with a device already added. It will also fail if the NUMA node that the driver is loaded on does not match the NUMA node the device is associated with. RFC->v1: Dropped nvdimm patch to submit later. It relies on code in libnvdimm development tree. Simplified queue_work_near to just convert node into a CPU. Split up drivers core and PM core patches. v1->v2: Renamed queue_work_near to queue_work_node Added WARN_ON_ONCE if we use queue_work_node with per-cpu workqueue v2->v3: Added Acked-by for queue_work_node patch Continued rename from _near to _node to be consistent with queue_work_node Renamed async_schedule_near_domain to async_schedule_node_domain Renamed async_schedule_near to async_schedule_node Added kerneldoc for new async_schedule_XXX functions Updated patch description for patch 4 to include data on potential gains v3->v4 Added patch to consolidate use of need_parent_lock Make asynchronous driver probing explicit about use of drvdata v4->v5 Added patch to move async_synchronize_full to address deadlock Added bit async_probe to act as mutex for probe/remove calls Added back nvdimm patch as code it relies on is now in Linus's tree Incorporated review comments on parent & device locking consolidation Rebased on latest linux-next v5->v6: Drop the "This patch" or "This change" from start of patch descriptions. Drop unnecessary parenthesis in first patch Use same wording for "selecting a CPU" in comments added in first patch Added kernel documentation for async_probe member of device Fixed up comments for async_schedule calls in patch 2 Moved code related setting async driver out of device.h and into dd.c Added Reviewed-by for several patches v6->v7: Fixed typo which had kernel doc refer to "lock" when I meant "unlock" Dropped "bool X:1" to "u8 X:1" from patch description Added async_driver to device_private structure to store driver Dropped unecessary code shuffle from async_probe patch Reordered patches to move fixes up to front Added Reviewed-by for several patches Updated cover page and patch descriptions throughout the set v7->v8: Replaced async_probe value with dead, only apply dead in device_del Dropped Reviewed-by from patch 2 due to significant changes Added Reviewed-by for patches reviewed by Luis Chamberlain v8->v9: Dropped patch 1 as it was applied, shifted remaining patches by 1 Added new patch 9 that adds test framework for NUMA and sequential init Tweaked what is now patch 1, and added Reviewed-by from Dan Williams v9->v10: Moved "dead" from device struct to device_private struct Added Reviewed-by from Rafael to patch 1 Rebased on latest linux-next --- Alexander Duyck (9): driver core: Establish order of operations for device_add and device_del via bitflag device core: Consolidate locking and unlocking of parent and device driver core: Probe devices asynchronously instead of the driver workqueue: Provide queue_work_node to queue work near a given NUMA node async: Add support for queueing on specific NUMA node driver core: Attach devices on CPU local to device node PM core: Use new async_schedule_dev command libnvdimm: Schedule device registration on node local to the device driver core: Rewrite test_async_driver_probe to cover serialization and NUMA affinity drivers/base/base.h | 8 + drivers/base/bus.c | 46 +---- drivers/base/core.c | 11 + drivers/base/dd.c | 160 +++++++++++++---- drivers/base/power/main.c | 12 + drivers/base/test/test_async_driver_probe.c | 261 +++++++++++++++++++++------ drivers/nvdimm/bus.c | 11 + include/linux/async.h | 82 ++++++++ include/linux/workqueue.h | 2 kernel/async.c | 53 +++-- kernel/workqueue.c | 84 +++++++++ 11 files changed, 564 insertions(+), 166 deletions(-) --