Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
sched/fair: Use full weight to __calc_delta()
Since we now use the full weight for avg_vruntime(), also make
__calc_delta() use the full value.
Since weight is effectively NICE_0_LOAD, this is 20 bits on 64bit.
This leaves 44 bits for delta_exec, which is ~16k seconds, way longer
than any one tick would ever be, so no worry about overflow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Shubhang Kaushik <shubhang@os.amperecomputing.com>
Link: https://patch.msgid.link/20260219080625.183283814%40infradead.org
+7
+7
kernel/sched/fair.c
+7
kernel/sched/fair.c
···
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update_sysctl();
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}
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+
#ifndef CONFIG_64BIT
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#define WMULT_CONST (~0U)
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#define WMULT_SHIFT 32
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···
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return mul_u64_u32_shr(delta_exec, fact, shift);
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}
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#else
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static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight *lw)
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{
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return (delta_exec * weight) / lw->weight;
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}
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#endif
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/*
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* delta /= w