btrfs: report congestion for NO_THRESHOLD workqueues#11
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Summary
Keep pending-work accounting for Btrfs workqueues even when they use
NO_THRESHOLD, and letbtrfs_workqueue_normal_congested()report congestion for those queues based on pending work versus online CPU count.Dynamic max-active behavior for thresholded workqueues is unchanged.
Why
NO_THRESHOLDqueues previously always reported uncongested, even when pending work was high. This hid backpressure from callers that use congestion as a signal.Compatibility
No userspace ABI, module contract, exported symbol, Kconfig, or dependency changes. Existing workqueue interfaces remain unchanged.
Validation
ARCH=umobject build forfs/btrfs/async-thread.o.scripts/checkpatch.pl --no-tree --file fs/btrfs/async-thread.cpassed.gelf.h, required byobjtool.