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Date:   Sun, 11 Dec 2022 23:33:50 +0100 (CET)
From:   Julia Lawall <julia.lawall@inria.fr>
To:     Tejun Heo <tj@kernel.org>
cc:     torvalds@linux-foundation.org, mingo@redhat.com,
        peterz@infradead.org, juri.lelli@redhat.com,
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Subject: Re: [PATCH 14/31] sched_ext: Implement BPF extensible scheduler
 class
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References: <20221130082313.3241517-1-tj@kernel.org> <20221130082313.3241517-15-tj@kernel.org>
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> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> new file mode 100644
> index 000000000000..f42464d66de4
> --- /dev/null
> +++ b/kernel/sched/ext.c
> @@ -0,0 +1,2780 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
> + * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
> + * Copyright (c) 2022 David Vernet <dvernet@meta.com>
> + */
> +#define SCX_OP_IDX(op)		(offsetof(struct sched_ext_ops, op) / sizeof(void (*)(void)))
> +
> +enum scx_internal_consts {
> +	SCX_NR_ONLINE_OPS	 = SCX_OP_IDX(init),
> +	SCX_DSP_DFL_MAX_BATCH	 = 32,

This definition of SCX_DSP_DFL_MAX_BATCH makes the dispatch queue have size
32.  The example central policy thus aborts if more than 32 tasks are woken
up at once.

julia