From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: Vineet Gupta <Vineet.Gupta1@synopsys.com>,
Lada Trimasova <Lada.Trimasova@synopsys.com>,
"linux-perf-users@vger.kernel.org"
<linux-perf-users@vger.kernel.org>
Cc: "peterz@infradead.org" <peterz@infradead.org>,
"linux-snps-arc@lists.infradead.org"
<linux-snps-arc@lists.infradead.org>,
Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Vince Weaver <vincent.weaver@maine.edu>,
Will Deacon <Will.Deacon@arm.com>, Ingo Molnar <mingo@kernel.org>
Subject: Re: Misleading hint to select CONFIG_PERF_EVENTS if driver sets PERF_PMU_CAP_NO_INTERRUPT
Date: Thu, 5 May 2016 18:51:09 +0530 [thread overview]
Message-ID: <572B48C5.6090401@synopsys.com> (raw)
In-Reply-To: <C2D7FE5348E1B147BCA15975FBA23075F4E9F42D@us01wembx1.internal.synopsys.com>
On Tuesday 26 April 2016 06:12 PM, Vineet Gupta wrote:
> On Friday 22 April 2016 06:56 PM, Lada Trimasova wrote:
>> I have a question about user-space perf handling error numbers.
>> The problem is that PMU interrupts are not supported in arc700
>> architecture and it is impossible to evaluate `perf record` command.
>> In our perf implementation we set PERF_PMU_CAP_NO_INTERRUPT flag so
>> core perf infrastructure knows we don't have interrupts.
>>
>> Kernel `sys_perf_event_open` handler checks if PMU interrupts are
>> supported and returns ENOTSUPP (524) error code.
>> I'd expect that perf implementation checks the return value of syscalls
>> and gives the user understandable error message.
>> But now I see:
>> --------------------------------->8-----------------------------------
>> # perf record ls
>> The sys_perf_event_open() syscall returned with 524 (Unknown error 524)
>> for event (cycles:ppp).
>> /bin/dmesg may provide additional information.
>> No CONFIG_PERF_EVENTS=y kernel support configured?
>> --------------------------------->8-----------------------------------
Guys, is the ABI change for returning -EOPNOTSUPP vs. -ENOTSUPP for
is_sampling_event() && (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT)
acceptable ? We could use this in userspace to print pretty rather than half
cooked error msg above !
-Vineet
WARNING: multiple messages have this Message-ID (diff)
From: Vineet.Gupta1@synopsys.com (Vineet Gupta)
To: linux-snps-arc@lists.infradead.org
Subject: Misleading hint to select CONFIG_PERF_EVENTS if driver sets PERF_PMU_CAP_NO_INTERRUPT
Date: Thu, 5 May 2016 18:51:09 +0530 [thread overview]
Message-ID: <572B48C5.6090401@synopsys.com> (raw)
In-Reply-To: <C2D7FE5348E1B147BCA15975FBA23075F4E9F42D@us01wembx1.internal.synopsys.com>
On Tuesday 26 April 2016 06:12 PM, Vineet Gupta wrote:
> On Friday 22 April 2016 06:56 PM, Lada Trimasova wrote:
>> I have a question about user-space perf handling error numbers.
>> The problem is that PMU interrupts are not supported in arc700
>> architecture and it is impossible to evaluate `perf record` command.
>> In our perf implementation we set PERF_PMU_CAP_NO_INTERRUPT flag so
>> core perf infrastructure knows we don't have interrupts.
>>
>> Kernel `sys_perf_event_open` handler checks if PMU interrupts are
>> supported and returns ENOTSUPP (524) error code.
>> I'd expect that perf implementation checks the return value of syscalls
>> and gives the user understandable error message.
>> But now I see:
>> --------------------------------->8-----------------------------------
>> # perf record ls
>> The sys_perf_event_open() syscall returned with 524 (Unknown error 524)
>> for event (cycles:ppp).
>> /bin/dmesg may provide additional information.
>> No CONFIG_PERF_EVENTS=y kernel support configured?
>> --------------------------------->8-----------------------------------
Guys, is the ABI change for returning -EOPNOTSUPP vs. -ENOTSUPP for
is_sampling_event() && (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT)
acceptable ? We could use this in userspace to print pretty rather than half
cooked error msg above !
-Vineet
next prev parent reply other threads:[~2016-05-05 13:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-22 13:25 Misleading hint to select CONFIG_PERF_EVENTS if driver sets PERF_PMU_CAP_NO_INTERRUPT Lada Trimasova
2016-04-22 13:25 ` Lada Trimasova
2016-04-26 10:57 ` Lada Trimasova
2016-04-26 10:57 ` Lada Trimasova
2016-04-26 12:42 ` Vineet Gupta
2016-04-26 12:42 ` Vineet Gupta
2016-04-27 15:13 ` Lada Trimasova
2016-04-27 15:13 ` Lada Trimasova
[not found] ` <1461770030.5970.8.camel__5728.3871378333$1461770054$gmane$org@synopsys.com>
2016-04-28 4:35 ` Vineet Gupta
2016-04-28 4:35 ` Vineet Gupta
2016-05-05 13:21 ` Vineet Gupta [this message]
2016-05-05 13:21 ` Vineet Gupta
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