From: Alexei Starovoitov <ast@plumgrid.com>
To: Steven Rostedt <rostedt@goodmis.org>
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>,
"David S. Miller" <davem@davemloft.net>,
Daniel Borkmann <daniel@iogearbox.net>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-api@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 tip 3/8] tracing: allow BPF programs to call bpf_ktime_get_ns()
Date: Thu, 19 Mar 2015 08:38:05 -0700 [thread overview]
Message-ID: <550AED5D.3010700@plumgrid.com> (raw)
In-Reply-To: <20150319111124.38f53061@gandalf.local.home>
On 3/19/15 8:11 AM, Steven Rostedt wrote:
> On Mon, 16 Mar 2015 14:49:39 -0700
> Alexei Starovoitov <ast@plumgrid.com> wrote:
>
>> bpf_ktime_get_ns() is used by programs to compue time delta between events
>
> "compute"
ok :)
>> + [BPF_FUNC_ktime_get_ns] = {
>> + .func = bpf_ktime_get_ns,
>> + .gpl_only = true,
>> + .ret_type = RET_INTEGER,
>
> Hmm, a nanosecond value returned as integer? Is there a way to make
> this a 64 bit return type, or is RET_INTEGER default to 64 bits in BPF
> functions?
RET_INTEGER doesn't mean C 'int' width. It means non-pointer and
non-void value. The return value is always promoted to full
register width which is 64-bit.
next prev parent reply other threads:[~2015-03-19 15:38 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-16 21:49 [PATCH v7 tip 0/8] tracing: attach eBPF programs to kprobes Alexei Starovoitov
2015-03-16 21:49 ` [PATCH v7 tip 1/8] bpf: make internal bpf API independent of CONFIG_BPF_SYSCALL ifdefs Alexei Starovoitov
2015-03-16 21:49 ` [PATCH v7 tip 2/8] tracing: attach BPF programs to kprobes Alexei Starovoitov
2015-03-19 15:07 ` Steven Rostedt
2015-03-19 15:33 ` Alexei Starovoitov
2015-03-20 8:35 ` Masami Hiramatsu
2015-03-16 21:49 ` [PATCH v7 tip 3/8] tracing: allow BPF programs to call bpf_ktime_get_ns() Alexei Starovoitov
2015-03-19 15:11 ` Steven Rostedt
2015-03-19 15:38 ` Alexei Starovoitov [this message]
2015-03-19 15:41 ` Steven Rostedt
2015-03-16 21:49 ` [PATCH v7 tip 4/8] tracing: allow BPF programs to call bpf_trace_printk() Alexei Starovoitov
2015-03-19 15:29 ` Steven Rostedt
2015-03-19 15:51 ` Alexei Starovoitov
2015-03-16 21:49 ` [PATCH v7 tip 5/8] samples: bpf: simple non-portable kprobe filter example Alexei Starovoitov
2015-03-19 15:50 ` Steven Rostedt
2015-03-19 15:53 ` Alexei Starovoitov
2015-03-16 21:49 ` [PATCH v7 tip 6/8] samples: bpf: counting example for kfree_skb and write syscall Alexei Starovoitov
2015-03-16 21:49 ` [PATCH v7 tip 7/8] samples: bpf: IO latency analysis (iosnoop/heatmap) Alexei Starovoitov
2015-03-16 21:49 ` [PATCH v7 tip 8/8] samples: bpf: kmem_alloc/free tracker Alexei Starovoitov
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=550AED5D.3010700@plumgrid.com \
--to=ast@plumgrid.com \
--cc=a.p.zijlstra@chello.nl \
--cc=acme@infradead.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--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=rostedt@goodmis.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox