From: Steven Rostedt <rostedt@goodmis.org>
To: Alexei Starovoitov <ast@fb.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"David S. Miller" <davem@davemloft.net>,
Daniel Borkmann <daniel@iogearbox.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
netdev <netdev@vger.kernel.org>, kernel-team <kernel-team@fb.com>,
linux-api <linux-api@vger.kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH v7 bpf-next 06/10] tracepoint: compute num_args at build time
Date: Wed, 28 Mar 2018 14:54:31 -0400 [thread overview]
Message-ID: <20180328145431.687643bc@gandalf.local.home> (raw)
In-Reply-To: <a5c8ff7c-8185-a3fd-89eb-45ddc099c03b@fb.com>
On Wed, 28 Mar 2018 11:19:34 -0700
Alexei Starovoitov <ast@fb.com> wrote:
> On 3/28/18 11:10 AM, Steven Rostedt wrote:
> > On Wed, 28 Mar 2018 11:03:24 -0700
> > Alexei Starovoitov <ast@fb.com> wrote:
> >
> >> I can live with this overhead if Mathieu insists,
> >> but I prefer to keep it in 'struct tracepoint'.
> >>
> >> Thoughts?
> >
> > I'm fine with keeping it as is. We could probably use it for future
> > enhancements in perf and ftrace.
> >
> > Perhaps, we should just add a:
> >
> > #ifdef CONFIG_BPF_EVENTS
> >
> > Around the use cases of num_args.
>
> it sounds like a good idea, but implementation wise
> it will be ifdef CONFIG_BPF_EVENTS around u32 num_args;
> in struct tracepoint and similar double definition of
> DEFINE_TRACE_FN. One that uses num_args to init
> struct tracepoint and one that doesn't ?
> Feels like serious uglification of already macros heavy code.
> Also what it will address?
32bit bloat ;-)
But I agree, it's not worth uglifying it.
-- Steve
> cache hot/cold argument clearly doesn't apply.
next prev parent reply other threads:[~2018-03-28 18:54 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-28 2:10 [PATCH v7 bpf-next 00/10] bpf, tracing: introduce bpf raw tracepoints Alexei Starovoitov
2018-03-28 2:10 ` [PATCH v7 bpf-next 01/10] treewide: remove large struct-pass-by-value from tracepoint arguments Alexei Starovoitov
2018-03-28 2:10 ` [PATCH v7 bpf-next 02/10] net/mediatek: disambiguate mt76 vs mt7601u trace events Alexei Starovoitov
2018-03-28 2:10 ` [PATCH v7 bpf-next 03/10] net/mac802154: disambiguate mac80215 vs mac802154 " Alexei Starovoitov
2018-03-28 2:10 ` [PATCH v7 bpf-next 04/10] net/wireless/iwlwifi: fix iwlwifi_dev_ucode_error tracepoint Alexei Starovoitov
2018-03-28 2:11 ` [PATCH v7 bpf-next 05/10] macro: introduce COUNT_ARGS() macro Alexei Starovoitov
2018-03-28 2:11 ` [PATCH v7 bpf-next 06/10] tracepoint: compute num_args at build time Alexei Starovoitov
2018-03-28 13:49 ` Mathieu Desnoyers
2018-03-28 16:43 ` Alexei Starovoitov
2018-03-28 17:04 ` Steven Rostedt
2018-03-28 17:10 ` Alexei Starovoitov
2018-03-28 17:38 ` Steven Rostedt
2018-03-28 18:03 ` Alexei Starovoitov
2018-03-28 18:10 ` Steven Rostedt
2018-03-28 18:19 ` Alexei Starovoitov
2018-03-28 18:54 ` Steven Rostedt [this message]
2018-03-28 19:22 ` Mathieu Desnoyers
2018-03-28 19:25 ` Alexei Starovoitov
2018-03-28 19:32 ` Steven Rostedt
2018-03-28 19:38 ` Steven Rostedt
2018-03-28 19:47 ` Mathieu Desnoyers
2018-03-28 17:14 ` Mathieu Desnoyers
2018-03-28 2:11 ` [PATCH v7 bpf-next 07/10] bpf: introduce BPF_RAW_TRACEPOINT Alexei Starovoitov
2018-03-28 17:41 ` Steven Rostedt
2018-03-28 2:11 ` [PATCH v7 bpf-next 08/10] libbpf: add bpf_raw_tracepoint_open helper Alexei Starovoitov
2018-03-28 2:11 ` [PATCH v7 bpf-next 09/10] samples/bpf: raw tracepoint test Alexei Starovoitov
2018-03-28 2:11 ` [PATCH v7 bpf-next 10/10] selftests/bpf: test for bpf_get_stackid() from raw tracepoints Alexei Starovoitov
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