From: Oleg Nesterov <oleg@redhat.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
"zhangwei(Jovi)" <jovi.zhangwei@huawei.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/4] tracing/kprobes: Don't pass addr=ip to perf_trace_buf_submit()
Date: Mon, 1 Jul 2013 21:45:55 +0200 [thread overview]
Message-ID: <20130701194555.GA31476@redhat.com> (raw)
In-Reply-To: <1372704916.22688.12.camel@gandalf.local.home>
On 07/01, Steven Rostedt wrote:
>
> On Thu, 2013-06-20 at 19:38 +0200, Oleg Nesterov wrote:
> > kprobe_perf_func() and kretprobe_perf_func() pass addr=ip to
> > perf_trace_buf_submit() for no reason.
> >
> > This sets perf_sample_data->addr for PERF_SAMPLE_ADDR, we already
> > have perf_sample_data->ip initialized if PERF_SAMPLE_IP.
>
> This change log is confusing. I have no idea what this is trying to fix.
> Can you explain what is the issue here and what this change fixes.
Sorry for confusion, this fixes nothing.
Just there is no reason to pass "addr = kp.addr", we report it in entry.
Note also that kprobes is the last user perf_trace_buf_submit(addr != 0),
perhaps we can kill this arg and __perf_addr().
See also 32520b2c6 "Don't pass addr=ip to perf_trace_buf_submit()".
> Thanks,
>
> -- Steve
>
> >
> > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> > ---
> > kernel/trace/trace_kprobe.c | 6 ++----
> > 1 files changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> > index 3432652..141c682 100644
> > --- a/kernel/trace/trace_kprobe.c
> > +++ b/kernel/trace/trace_kprobe.c
> > @@ -1163,8 +1163,7 @@ kprobe_perf_func(struct trace_probe *tp, struct pt_regs *regs)
> > entry->ip = (unsigned long)tp->rp.kp.addr;
> > memset(&entry[1], 0, dsize);
> > store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
> > - perf_trace_buf_submit(entry, size, rctx,
> > - entry->ip, 1, regs, head, NULL);
> > + perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
> > }
> >
> > /* Kretprobe profile handler */
> > @@ -1197,8 +1196,7 @@ kretprobe_perf_func(struct trace_probe *tp, struct kretprobe_instance *ri,
> > entry->func = (unsigned long)tp->rp.kp.addr;
> > entry->ret_ip = (unsigned long)ri->ret_addr;
> > store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
> > - perf_trace_buf_submit(entry, size, rctx,
> > - entry->ret_ip, 1, regs, head, NULL);
> > + perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
> > }
> > #endif /* CONFIG_PERF_EVENTS */
> >
>
>
next prev parent reply other threads:[~2013-07-01 19:50 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 17:37 [PATCH v2 0/4] tracing/kprobes: perf_trace_buf_*() optimization + cleanups Oleg Nesterov
2013-06-20 17:38 ` [PATCH v2 1/4] tracing/kprobes: Avoid perf_trace_buf_*() if ->perf_events is empty Oleg Nesterov
2013-06-20 17:38 ` [PATCH v2 2/4] tracing/kprobes: Kill probe_enable_lock Oleg Nesterov
2013-06-20 17:38 ` [PATCH v2 3/4] tracing/kprobes: Don't pass addr=ip to perf_trace_buf_submit() Oleg Nesterov
2013-07-01 18:55 ` Steven Rostedt
2013-07-01 19:45 ` Oleg Nesterov [this message]
2013-06-20 17:38 ` [PATCH v2 4/4] tracing/kprobes: Turn trace_probe->files into list_head Oleg Nesterov
2013-07-01 19:08 ` Steven Rostedt
2013-07-01 19:36 ` Oleg Nesterov
2013-07-01 19:55 ` Steven Rostedt
2013-06-20 18:42 ` [PATCH v2 0/4] tracing/kprobes: perf_trace_buf_*() optimization + cleanups Steven Rostedt
2013-06-21 2:25 ` Masami Hiramatsu
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=20130701194555.GA31476@redhat.com \
--to=oleg@redhat.com \
--cc=jovi.zhangwei@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=masami.hiramatsu.pt@hitachi.com \
--cc=rostedt@goodmis.org \
--cc=srikar@linux.vnet.ibm.com \
/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;
as well as URLs for NNTP newsgroup(s).