All of lore.kernel.org
 help / color / mirror / Atom feed
From: Steven Rostedt <rostedt@goodmis.org>
To: Alexei Starovoitov <ast@plumgrid.com>
Cc: Ingo Molnar <mingo@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Arnaldo Carvalho de Melo <acme@infradead.org>,
	Jiri Olsa <jolsa@redhat.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	Linux API <linux-api@vger.kernel.org>,
	Network Development <netdev@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH v3 linux-trace 4/8] samples: bpf: simple tracing example in C
Date: Tue, 10 Feb 2015 07:27:01 -0500	[thread overview]
Message-ID: <20150210072701.547a5385@grimm.local.home> (raw)
In-Reply-To: <CAMEtUuyCmO+N2SOTNXfOVnRA59TWsZczPCJBWsB+h0E45NxHPA@mail.gmail.com>

On Mon, 9 Feb 2015 21:47:42 -0800
Alexei Starovoitov <ast@plumgrid.com> wrote:

> On Mon, Feb 9, 2015 at 9:45 PM, Alexei Starovoitov <ast@plumgrid.com> wrote:
> > I thought we already stated that.
> > Here is the quote from perf_event.h:
> >          *      # The RAW record below is opaque data wrt the ABI
> >          *      #
> >          *      # That is, the ABI doesn't make any promises wrt to
> >          *      # the stability of its content, it may vary depending
> >          *      # on event, hardware, kernel version and phase of
> >          *      # the moon.
> >          *      #
> >          *      # In other words, PERF_SAMPLE_RAW contents are not an ABI.
> >
> > and this example is reading PERF_SAMPLE_RAW events and
> > uses locally defined structs to print them for simplicity.
> 
> to underline my point once more:
> addition of bpf doesn't change at all what PERF_SAMPLE_RAW already
> delivers to user space.
> so no new ABIs anywhere.

Again, it we give an example of how to hard code the data, definitely
expect this to show up in user space. Users are going to look at this
code to learn how to use eBPF. I really want it to do it the correct
way instead of the 'easy' way. Because whatever way we have it here,
will be the way we will see it out in the wild.

-- Steve

WARNING: multiple messages have this Message-ID (diff)
From: Steven Rostedt <rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org>
To: Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org>
Cc: Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Namhyung Kim <namhyung-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Arnaldo Carvalho de Melo
	<acme-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
	Jiri Olsa <jolsa-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	Masami Hiramatsu
	<masami.hiramatsu.pt-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>,
	Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Network Development
	<netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Linus Torvalds
	<torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Subject: Re: [PATCH v3 linux-trace 4/8] samples: bpf: simple tracing example in C
Date: Tue, 10 Feb 2015 07:27:01 -0500	[thread overview]
Message-ID: <20150210072701.547a5385@grimm.local.home> (raw)
In-Reply-To: <CAMEtUuyCmO+N2SOTNXfOVnRA59TWsZczPCJBWsB+h0E45NxHPA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On Mon, 9 Feb 2015 21:47:42 -0800
Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org> wrote:

> On Mon, Feb 9, 2015 at 9:45 PM, Alexei Starovoitov <ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org> wrote:
> > I thought we already stated that.
> > Here is the quote from perf_event.h:
> >          *      # The RAW record below is opaque data wrt the ABI
> >          *      #
> >          *      # That is, the ABI doesn't make any promises wrt to
> >          *      # the stability of its content, it may vary depending
> >          *      # on event, hardware, kernel version and phase of
> >          *      # the moon.
> >          *      #
> >          *      # In other words, PERF_SAMPLE_RAW contents are not an ABI.
> >
> > and this example is reading PERF_SAMPLE_RAW events and
> > uses locally defined structs to print them for simplicity.
> 
> to underline my point once more:
> addition of bpf doesn't change at all what PERF_SAMPLE_RAW already
> delivers to user space.
> so no new ABIs anywhere.

Again, it we give an example of how to hard code the data, definitely
expect this to show up in user space. Users are going to look at this
code to learn how to use eBPF. I really want it to do it the correct
way instead of the 'easy' way. Because whatever way we have it here,
will be the way we will see it out in the wild.

-- Steve

  reply	other threads:[~2015-02-10 12:26 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-10  3:45 [PATCH v3 linux-trace 0/8] tracing: attach eBPF programs to tracepoints/syscalls/kprobe Alexei Starovoitov
2015-02-10  3:45 ` Alexei Starovoitov
2015-02-10  3:45 ` [PATCH v3 linux-trace 1/8] tracing: attach eBPF programs to tracepoints and syscalls Alexei Starovoitov
2015-02-10  3:45   ` Alexei Starovoitov
2015-02-10  4:46   ` Steven Rostedt
2015-02-10  4:46     ` Steven Rostedt
2015-02-10  5:13   ` Steven Rostedt
2015-02-10  5:13     ` Steven Rostedt
2015-02-10  3:45 ` [PATCH v3 linux-trace 2/8] tracing: allow eBPF programs to call ktime_get_ns() Alexei Starovoitov
2015-02-10  3:45 ` [PATCH v3 linux-trace 3/8] samples: bpf: simple tracing example in eBPF assembler Alexei Starovoitov
2015-02-10  3:45 ` [PATCH v3 linux-trace 4/8] samples: bpf: simple tracing example in C Alexei Starovoitov
2015-02-10  4:08   ` Steven Rostedt
2015-02-10  5:16     ` Steven Rostedt
2015-02-10  5:16       ` Steven Rostedt
2015-02-10  5:45       ` Alexei Starovoitov
2015-02-10  5:47         ` Alexei Starovoitov
2015-02-10  5:47           ` Alexei Starovoitov
2015-02-10 12:27           ` Steven Rostedt [this message]
2015-02-10 12:27             ` Steven Rostedt
2015-02-10 12:24         ` Steven Rostedt
2015-02-10 12:24           ` Steven Rostedt
2015-02-10  4:12   ` Steven Rostedt
2015-02-10  4:12     ` Steven Rostedt
2015-02-10  3:45 ` [PATCH v3 linux-trace 5/8] samples: bpf: counting example for kfree_skb tracepoint and write syscall Alexei Starovoitov
2015-02-10  3:45   ` Alexei Starovoitov
2015-02-10  3:45 ` [PATCH v3 linux-trace 6/8] samples: bpf: IO latency analysis (iosnoop/heatmap) Alexei Starovoitov
2015-02-10  3:46 ` [PATCH v3 linux-trace 7/8] tracing: attach eBPF programs to kprobe/kretprobe Alexei Starovoitov
2015-02-10  3:46 ` [PATCH v3 linux-trace 8/8] samples: bpf: simple kprobe example Alexei Starovoitov
2015-02-10 14:55 ` [PATCH v3 linux-trace 0/8] tracing: attach eBPF programs to tracepoints/syscalls/kprobe Steven Rostedt
2015-02-10 14:55   ` Steven Rostedt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150210072701.547a5385@grimm.local.home \
    --to=rostedt@goodmis.org \
    --cc=acme@infradead.org \
    --cc=ast@plumgrid.com \
    --cc=jolsa@redhat.com \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masami.hiramatsu.pt@hitachi.com \
    --cc=mingo@kernel.org \
    --cc=namhyung@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.