From: Stephane Eranian <eranian@google.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, kim.phillips@amd.com, acme@redhat.com,
jolsa@redhat.com, songliubraving@fb.com
Subject: Re: [PATCH v6 10/12] perf tools: Improve IBS error handling
Date: Mon, 14 Mar 2022 19:01:49 -0700 [thread overview]
Message-ID: <CABPqkBSzc167wNbJpWu7msfZ-KrGu-nMtFdw-naN+M7Q0py-vA@mail.gmail.com> (raw)
In-Reply-To: <20220208211637.2221872-11-eranian@google.com>
Hi Kim,
On Tue, Feb 8, 2022 at 1:17 PM Stephane Eranian <eranian@google.com> wrote:
>
> From: Kim Phillips <kim.phillips@amd.com>
>
> improve the error message returned on failed perf_event_open() on AMD when
> using IBS.
>
> Output of executing 'perf record -e ibs_op// true' BEFORE this patch:
>
> The sys_perf_event_open() syscall returned with 22 (Invalid argument)for event (ibs_op//u).
> /bin/dmesg | grep -i perf may provide additional information.
>
> Output after:
>
> AMD IBS cannot exclude kernel events. Try running at a higher privilege level.
>
> Output of executing 'sudo perf record -e ibs_op// true' BEFORE this patch:
>
> Error:
> The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (ibs_op//).
> /bin/dmesg | grep -i perf may provide additional information.
>
> Output after:
>
> Error:
> AMD IBS may only be available in system-wide/per-cpu mode. Try using -a, or -C and workload affinity
>
> Signed-off-by: Kim Phillips <kim.phillips@amd.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Joao Martins <joao.m.martins@oracle.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Michael Petlan <mpetlan@redhat.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Robert Richter <robert.richter@amd.com>
> Cc: Stephane Eranian <eranian@google.com>
> ---
> tools/perf/util/evsel.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 22d3267ce294..d42f63a484df 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2847,9 +2847,22 @@ static bool find_process(const char *name)
> return ret ? false : true;
> }
>
> +static bool is_amd(const char *arch, const char *cpuid)
> +{
> + return arch && !strcmp("x86", arch) && cpuid && strstarts(cpuid, "AuthenticAMD");
> +}
> +
> +static bool is_amd_ibs(struct evsel *evsel)
> +{
> + return evsel->core.attr.precise_ip || !strncmp(evsel->pmu_name, "ibs", 3);
> +}
> +
> int evsel__open_strerror(struct evsel *evsel, struct target *target,
> int err, char *msg, size_t size)
> {
> + struct perf_env *env = evsel__env(evsel);
> + const char *arch = perf_env__arch(env);
> + const char *cpuid = perf_env__cpuid(env);
This code dies for me on the latest tip.git because env = NULL and
perf_env_cpuid() is broken for NULL argument.
I don't quite know where this env global variable is set but I hope
there is a better way of doing this, maybe using
the evsel__env() function in the same util/evsel.c file.
Similarly, the is_amd_ibs() suffers from a NULL pointer dereference
because evsel->pmu_name maybe NULL:
$ perf record -e rc2 .....
causes a NULL pmu_name.
Could you please send me an updated version to integrate with the
branch sampling code?
Thanks.
>
> char sbuf[STRERR_BUFSIZE];
> int printed = 0, enforced = 0;
>
> @@ -2949,6 +2962,17 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
> return scnprintf(msg, size,
> "Invalid event (%s) in per-thread mode, enable system wide with '-a'.",
> evsel__name(evsel));
> + if (is_amd(arch, cpuid)) {
> + if (is_amd_ibs(evsel)) {
> + if (evsel->core.attr.exclude_kernel)
> + return scnprintf(msg, size,
> + "AMD IBS can't exclude kernel events. Try running at a higher privilege level.");
> + if (!evsel->core.system_wide)
> + return scnprintf(msg, size,
> + "AMD IBS may only be available in system-wide/per-cpu mode. Try using -a, or -C and workload affinity");
> + }
> + }
> +
> break;
> case ENODATA:
> return scnprintf(msg, size, "Cannot collect data source with the load latency event alone. "
> --
> 2.35.0.263.gb82422642f-goog
>
next prev parent reply other threads:[~2022-03-15 2:02 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 21:16 [PATCH v6 00/12] perf/x86/amd: Add AMD Fam19h Branch Sampling support Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 01/12] perf/core: add perf_clear_branch_entry_bitfields() helper Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 02/12] x86/cpufeatures: add AMD Fam19h Branch Sampling feature Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 03/12] perf/x86/amd: add AMD Fam19h Branch Sampling support Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 04/12] perf/x86/amd: add branch-brs helper event for Fam19h BRS Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 05/12] perf/x86/amd: enable branch sampling priv level filtering Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 06/12] perf/x86/amd: add AMD branch sampling period adjustment Stephane Eranian
2022-02-09 15:32 ` Peter Zijlstra
2022-03-04 15:45 ` Peter Zijlstra
2022-03-09 23:03 ` Stephane Eranian
2022-03-15 12:08 ` Peter Zijlstra
2022-03-17 17:11 ` Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 07/12] perf/x86/amd: make Zen3 branch sampling opt-in Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 08/12] ACPI: add perf low power callback Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 09/12] perf/x86/amd: add idle hooks for branch sampling Stephane Eranian
2022-02-08 21:16 ` [PATCH v6 10/12] perf tools: Improve IBS error handling Stephane Eranian
2022-02-09 15:47 ` Arnaldo Carvalho de Melo
2022-03-15 6:49 ` Ravi Bangoria
2022-03-15 2:01 ` Stephane Eranian [this message]
2022-03-15 6:23 ` Ravi Bangoria
2022-03-15 7:12 ` Stephane Eranian
2022-03-15 7:45 ` Ravi Bangoria
2022-03-16 0:03 ` Stephane Eranian
2022-03-16 11:07 ` Ravi Bangoria
2022-03-16 11:16 ` Ravi Bangoria
2022-02-08 21:16 ` [PATCH v6 11/12] perf tools: Improve error handling of AMD Branch Sampling Stephane Eranian
2022-02-16 14:17 ` Arnaldo Carvalho de Melo
2022-02-08 21:16 ` [PATCH v6 12/12] perf report: add addr_from/addr_to sort dimensions Stephane Eranian
2022-02-16 14:21 ` Arnaldo Carvalho de Melo
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=CABPqkBSzc167wNbJpWu7msfZ-KrGu-nMtFdw-naN+M7Q0py-vA@mail.gmail.com \
--to=eranian@google.com \
--cc=acme@redhat.com \
--cc=jolsa@redhat.com \
--cc=kim.phillips@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=songliubraving@fb.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).