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cd047867ee
rb_add_augmented_cached() links the new node and then calls
->propagate() from the parent up to the root to bring the augmented
data of the ancestors up to date. It marks that as "suboptimal": every
augmented user that open-codes its insertion (interval trees, vmalloc,
drm_mm, gpu buddy, ...) instead folds the new node's value into each
ancestor while walking down, which touches no sibling and needs no
second pass. ->propagate() has to read both children of every
ancestor until it finds one whose value did not change.
Add a ->merge() callback to struct rb_augment_callbacks that folds the
augmented data of a node being inserted into one of its future
ancestors, and use it on the descent. RB_DECLARE_CALLBACKS() derives
it from the RB_AUG() list, so every user of the template gets it for
free, and sched/eevdf, the only caller of the helper, needs no change.
The new node's augmented data must describe the node alone before the
call. That was already required, since ->propagate() read it, and
sched/eevdf sets it up that way.
Measured with rbtree_test's cached augmented test switched to
rb_add_augmented_cached() (next patch), nnodes cached insert+delete,
median of 5 runs, for reference also the open-coded descent used by
augmented test 1. Raspberry Pi 4 Model B (Cortex-A72, 1.8 GHz), arch
timer ticks (54 MHz):
nnodes open-coded before after
100 459 500 442 (-11.6%)
10000 182046 186144 180208 (-3.2%)
100000 5533679 5711647
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| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| cxl | ||
| drm | ||
| dt-bindings | ||
| hyperv | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||
| Kbuild | ||