diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-09-26 21:43:56 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-02-23 18:04:10 +0100 |
| commit | 4823725d9d1d9cc5b36647e0cb8ff616cad6536f (patch) | |
| tree | d423204b77edb9e25d344b483245e67bf28130fc /kernel/sched/debug.c | |
| parent | 9fe89f022c05d99c052d6bc088b82d4ff83bf463 (diff) | |
sched/fair: Increase weight bits for avg_vruntime
Due to the zero_vruntime patch, the deltas are now a lot smaller and
measurement with kernel-build and hackbench runs show about 45 bits
used.
This ensures avg_vruntime() tracks the full weight range, reducing
numerical artifacts in reweight and the like.
Also, lets keep the paranoid debug code around fow now.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Shubhang Kaushik <shubhang@os.amperecomputing.com>
Link: https://patch.msgid.link/20260219080624.942813440%40infradead.org
Diffstat (limited to 'kernel/sched/debug.c')
| -rw-r--r-- | kernel/sched/debug.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index b24f40f05019..6246008c431e 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -8,6 +8,7 @@ */ #include <linux/debugfs.h> #include <linux/nmi.h> +#include <linux/log2.h> #include "sched.h" /* @@ -901,10 +902,13 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) { - s64 left_vruntime = -1, zero_vruntime, right_vruntime = -1, left_deadline = -1, spread; + s64 left_vruntime = -1, right_vruntime = -1, left_deadline = -1, spread; + s64 zero_vruntime = -1, sum_w_vruntime = -1; struct sched_entity *last, *first, *root; struct rq *rq = cpu_rq(cpu); + unsigned int sum_shift; unsigned long flags; + u64 sum_weight; #ifdef CONFIG_FAIR_GROUP_SCHED SEQ_printf(m, "\n"); @@ -925,6 +929,9 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) if (last) right_vruntime = last->vruntime; zero_vruntime = cfs_rq->zero_vruntime; + sum_w_vruntime = cfs_rq->sum_w_vruntime; + sum_weight = cfs_rq->sum_weight; + sum_shift = cfs_rq->sum_shift; raw_spin_rq_unlock_irqrestore(rq, flags); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "left_deadline", @@ -933,6 +940,11 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) SPLIT_NS(left_vruntime)); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "zero_vruntime", SPLIT_NS(zero_vruntime)); + SEQ_printf(m, " .%-30s: %Ld (%d bits)\n", "sum_w_vruntime", + sum_w_vruntime, ilog2(abs(sum_w_vruntime))); + SEQ_printf(m, " .%-30s: %Lu\n", "sum_weight", + sum_weight); + SEQ_printf(m, " .%-30s: %u\n", "sum_shift", sum_shift); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "avg_vruntime", SPLIT_NS(avg_vruntime(cfs_rq))); SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "right_vruntime", |