[DTrace-devel] [PATCH] Free the DIFO for a probe once it is loaded

[Nick Alcock]

On 25 Jul 2025, Kris Van Hees verbalised:

> When a lot of probes are being probed, keeping all DIFO around consumes
> a lot of memory.  Once the BPF program is loaded, the DIFO can be freed.

DIFO? BPFO, surely :)

... the attached patch only seems to free anything new on failure, not
on after-loading.

> +fail:
> +	dt_difo_free(dtp, prp->difo);
> +	prp->difo = NULL;
> +	return -1;
[...]
> +fail:
> +	dt_difo_free(dtp, prp->difo);
> +	prp->difo = NULL;
> +	return 0;	// FIXME in dt_bpf_make_progs() this is a fatal error; should we do the same here?