From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: oleg@redhat.com, peterz@infradead.org, srikar@linux.vnet.ibm.com,
rostedt@goodmis.org, acme@kernel.org, ananth@linux.vnet.ibm.com,
akpm@linux-foundation.org, alexander.shishkin@linux.intel.com,
alexis.berlemont@gmail.com, corbet@lwn.net,
dan.j.williams@intel.com, jolsa@redhat.com, kan.liang@intel.com,
kjlx@templeofstupid.com, kstewart@linuxfoundation.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, milian.wolff@kdab.com, mingo@redhat.com,
namhyung@kernel.org, naveen.n.rao@linux.vnet.ibm.com,
pc@us.ibm.com, tglx@linutronix.de, yao.jin@linux.intel.com,
fengguang.wu@intel.com, jglisse@redhat.com
Subject: Re: [PATCH v2 9/9] perf probe: Support SDT markers having reference counter (semaphore)
Date: Mon, 9 Apr 2018 16:28:56 +0900 [thread overview]
Message-ID: <20180409162856.df4c32b840eb5f2ef8c028f1@kernel.org> (raw)
In-Reply-To: <20180404083110.18647-10-ravi.bangoria@linux.vnet.ibm.com>
Hi Ravi,
On Wed, 4 Apr 2018 14:01:10 +0530
Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> wrote:
> With this, perf buildid-cache will save SDT markers with reference
> counter in probe cache. Perf probe will be able to probe markers
> having reference counter. Ex,
>
> # readelf -n /tmp/tick | grep -A1 loop2
> Name: loop2
> ... Semaphore: 0x0000000010020036
>
> # ./perf buildid-cache --add /tmp/tick
> # ./perf probe sdt_tick:loop2
> # ./perf stat -e sdt_tick:loop2 /tmp/tick
> hi: 0
> hi: 1
> hi: 2
> ^C
> Performance counter stats for '/tmp/tick':
> 3 sdt_tick:loop2
> 2.561851452 seconds time elapsed
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
> ---
> tools/perf/util/probe-event.c | 18 ++++++++++++++---
> tools/perf/util/probe-event.h | 1 +
> tools/perf/util/probe-file.c | 34 ++++++++++++++++++++++++++------
> tools/perf/util/probe-file.h | 1 +
> tools/perf/util/symbol-elf.c | 46 ++++++++++++++++++++++++++++++++-----------
> tools/perf/util/symbol.h | 7 +++++++
> 6 files changed, 86 insertions(+), 21 deletions(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index e1dbc98..b3a1330 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -1832,6 +1832,12 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
> tp->offset = strtoul(fmt2_str, NULL, 10);
> }
>
> + if (tev->uprobes) {
> + fmt2_str = strchr(p, '(');
> + if (fmt2_str)
> + tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0);
> + }
> +
> tev->nargs = argc - 2;
> tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
> if (tev->args == NULL) {
> @@ -2054,15 +2060,21 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev)
> }
>
> /* Use the tp->address for uprobes */
> - if (tev->uprobes)
> + if (tev->uprobes) {
> err = strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address);
> - else if (!strncmp(tp->symbol, "0x", 2))
> + if (uprobe_ref_ctr_is_supported() &&
> + tp->ref_ctr_offset &&
> + err >= 0)
> + err = strbuf_addf(&buf, "(0x%lx)", tp->ref_ctr_offset);
If the kernel doesn't support uprobe_ref_ctr but the event requires
to increment uprobe_ref_ctr, I think we should (at least) warn user here.
> + } else if (!strncmp(tp->symbol, "0x", 2)) {
> /* Absolute address. See try_to_find_absolute_address() */
> err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
> tp->module ? ":" : "", tp->address);
> - else
> + } else {
> err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
> tp->module ? ":" : "", tp->symbol, tp->offset);
> + }
> +
> if (err)
> goto error;
>
> diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
> index 45b14f0..15a98c3 100644
> --- a/tools/perf/util/probe-event.h
> +++ b/tools/perf/util/probe-event.h
> @@ -27,6 +27,7 @@ struct probe_trace_point {
> char *symbol; /* Base symbol */
> char *module; /* Module name */
> unsigned long offset; /* Offset from symbol */
> + unsigned long ref_ctr_offset; /* SDT reference counter offset */
> unsigned long address; /* Actual address of the trace point */
> bool retprobe; /* Return probe flag */
> };
> diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
> index 4ae1123..ca0e524 100644
> --- a/tools/perf/util/probe-file.c
> +++ b/tools/perf/util/probe-file.c
> @@ -697,8 +697,16 @@ int probe_cache__add_entry(struct probe_cache *pcache,
> #ifdef HAVE_GELF_GETNOTE_SUPPORT
> static unsigned long long sdt_note__get_addr(struct sdt_note *note)
> {
> - return note->bit32 ? (unsigned long long)note->addr.a32[0]
> - : (unsigned long long)note->addr.a64[0];
> + return note->bit32 ?
> + (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
> + (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
> +}
> +
> +static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
> +{
> + return note->bit32 ?
> + (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
> + (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
> }
>
> static const char * const type_to_suffix[] = {
> @@ -776,14 +784,21 @@ static char *synthesize_sdt_probe_command(struct sdt_note *note,
> {
> struct strbuf buf;
> char *ret = NULL, **args;
> - int i, args_count;
> + int i, args_count, err;
> + unsigned long long ref_ctr_offset;
>
> if (strbuf_init(&buf, 32) < 0)
> return NULL;
>
> - if (strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
> - sdtgrp, note->name, pathname,
> - sdt_note__get_addr(note)) < 0)
> + err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
> + sdtgrp, note->name, pathname,
> + sdt_note__get_addr(note));
> +
> + ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
> + if (uprobe_ref_ctr_is_supported() && ref_ctr_offset && err >= 0)
> + err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
We don't have to care about uprobe_ref_ctr support here, because
this information will be just cached, not directly written to
uprobe_events.
Other parts look good to me.
Thanks,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2018-04-09 7:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-04 8:31 [PATCH v2 0/9] trace_uprobe: Support SDT markers having reference count (semaphore) Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 1/9] Uprobe: Export vaddr <-> offset conversion functions Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 2/9] mm: Prefix vma_ to vaddr_to_offset() and offset_to_vaddr() Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 3/9] Uprobe: Move mmput() into free_map_info() Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 4/9] Uprobe: Rename map_info to uprobe_map_info Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 5/9] Uprobe: Export uprobe_map_info along with uprobe_{build/free}_map_info() Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 6/9] trace_uprobe: Support SDT markers having reference count (semaphore) Ravi Bangoria
2018-04-04 15:03 ` [RFC PATCH] trace_uprobe: trace_uprobe_mmap() can be static kbuild test robot
2018-04-04 15:03 ` [PATCH v2 6/9] trace_uprobe: Support SDT markers having reference count (semaphore) kbuild test robot
2018-04-04 8:31 ` [PATCH v2 7/9] trace_uprobe/sdt: Fix multiple update of same reference counter Ravi Bangoria
2018-04-04 13:18 ` kbuild test robot
2018-04-04 13:24 ` kbuild test robot
2018-04-09 13:17 ` Oleg Nesterov
2018-04-09 13:32 ` Ravi Bangoria
2018-04-09 13:41 ` Ravi Bangoria
2018-04-09 13:29 ` Oleg Nesterov
2018-04-10 8:19 ` Ravi Bangoria
2018-04-10 11:06 ` Oleg Nesterov
2018-04-11 4:28 ` Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 8/9] trace_uprobe/sdt: Document about " Ravi Bangoria
2018-04-04 8:31 ` [PATCH v2 9/9] perf probe: Support SDT markers having reference counter (semaphore) Ravi Bangoria
2018-04-09 7:28 ` Masami Hiramatsu [this message]
2018-04-09 8:29 ` Ravi Bangoria
2018-04-09 14:08 ` 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=20180409162856.df4c32b840eb5f2ef8c028f1@kernel.org \
--to=mhiramat@kernel.org \
--cc=acme@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=alexis.berlemont@gmail.com \
--cc=ananth@linux.vnet.ibm.com \
--cc=corbet@lwn.net \
--cc=dan.j.williams@intel.com \
--cc=fengguang.wu@intel.com \
--cc=jglisse@redhat.com \
--cc=jolsa@redhat.com \
--cc=kan.liang@intel.com \
--cc=kjlx@templeofstupid.com \
--cc=kstewart@linuxfoundation.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=milian.wolff@kdab.com \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=naveen.n.rao@linux.vnet.ibm.com \
--cc=oleg@redhat.com \
--cc=pc@us.ibm.com \
--cc=peterz@infradead.org \
--cc=ravi.bangoria@linux.vnet.ibm.com \
--cc=rostedt@goodmis.org \
--cc=srikar@linux.vnet.ibm.com \
--cc=tglx@linutronix.de \
--cc=yao.jin@linux.intel.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).