[DTrace-devel] [PATCH 2/8] sched: clean up unnecessary includes and functions

[Eugene Loh]

Reviewed-by: Eugene Loh <eugene.loh at oracle.com>

On 3/7/25 16:34, Kris Van Hees via DTrace-devel wrote:
> Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
> ---
>   libdtrace/dt_prov_sched.c | 30 ++----------------------------
>   1 file changed, 2 insertions(+), 28 deletions(-)
>
> diff --git a/libdtrace/dt_prov_sched.c b/libdtrace/dt_prov_sched.c
> index e05ef246..125d5891 100644
> --- a/libdtrace/dt_prov_sched.c
> +++ b/libdtrace/dt_prov_sched.c
> @@ -1,6 +1,6 @@
>   /*
>    * Oracle Linux DTrace.
> - * Copyright (c) 2023, 2024, Oracle and/or its affiliates. All rights reserved.
> + * Copyright (c) 2023, 2025, Oracle and/or its affiliates. All rights reserved.
>    * Licensed under the Universal Permissive License v 1.0 as shown at
>    * http://oss.oracle.com/licenses/upl.
>    *
> @@ -9,9 +9,6 @@
>   #include <assert.h>
>   #include <errno.h>
>   
> -#include <linux/perf_event.h>
> -#include <perfmon/pfmlib_perf_event.h>
> -
>   #include "dt_dctx.h"
>   #include "dt_cg.h"
>   #include "dt_provider_sdt.h"
> @@ -146,36 +143,13 @@ static int trampoline(dt_pcb_t *pcb, uint_t exitlbl)
>   	return 0;
>   }
>   
> -/*
> - * We need a custom enabling for on-cpu probes to ensure that the fbt function
> - * __perf_event_task_sched_in is called.  __perf_event_task_sched_in will not
> - * be called unless context switch perf events have been enabled, so we do that
> - * here by opening a context switch count perf event but not attaching anything
> - * to it to minimize overhead.  The alternative - attaching to
> - * cpc:::context_switches-all-1 and weeding out on- versus off-cpu events via a
> - * trampoline is too expensive.  This approach works stably across kernels
> - * because __perf_event_task_sched_in() is not static, so not potentially
> - * subject to inlining or other optimizations.
> - */
> -static void enable(dtrace_hdl_t *dtp, dt_probe_t *prp)
> -{
> -	return dt_sdt_enable(dtp, prp);
> -}
> -
> -static void detach(dtrace_hdl_t *dtp, const dt_probe_t *prp)
> -{
> -	if (prp->prv_data)
> -		close((int)(long)prp->prv_data);
> -}
> -
>   dt_provimpl_t	dt_sched = {
>   	.name		= prvname,
>   	.prog_type	= BPF_PROG_TYPE_UNSPEC,
>   	.populate	= &populate,
> -	.enable		= &enable,
> +	.enable		= &dt_sdt_enable,
>   	.load_prog	= &dt_bpf_prog_load,
>   	.trampoline	= &trampoline,
>   	.probe_info	= &dt_sdt_probe_info,
> -	.detach		= &detach,
>   	.destroy	= &dt_sdt_destroy,
>   };