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From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Yicong Yang <yangyicong@hisilicon.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org,
	linux-pci@vger.kernel.org
Cc: helgaas@kernel.org, gregkh@linuxfoundation.org,
	lorenzo.pieralisi@arm.com, will@kernel.org, mark.rutland@arm.com,
	mathieu.poirier@linaro.org, suzuki.poulose@arm.com,
	mike.leach@linaro.org, leo.yan@linaro.org,
	jonathan.cameron@huawei.com, song.bao.hua@hisilicon.com,
	john.garry@huawei.com, prime.zeng@huawei.com,
	liuqi115@huawei.com, zhangshaokun@hisilicon.com,
	yangyicong@hisilicon.com, linuxarm@huawei.com,
	alexander.shishkin@linux.intel.com
Subject: Re: [PATCH RESEND 0/4] Add support for HiSilicon PCIe Tune and Trace device
Date: Sat, 17 Apr 2021 16:56:35 +0300	[thread overview]
Message-ID: <8735vpf20c.fsf@ashishki-desk.ger.corp.intel.com> (raw)
In-Reply-To: <1618654631-42454-1-git-send-email-yangyicong@hisilicon.com>

Yicong Yang <yangyicong@hisilicon.com> writes:

> The reason for not using perf is because there is no current support
> for uncore tracing in the perf facilities.

Not unless you count

$ perf list|grep -ic uncore
77

> We have our own format
> of data and don't need perf doing the parsing.

Perf has AUX buffers, which are used for all kinds of own formats.

> A similar approach for implementing this function is ETM, which use
> sysfs for configuring and a character device for dumping data.

And also perf. One reason ETM has a sysfs interface is because the
driver predates perf's AUX buffers. Can't say if it's the only
reason. I'm assuming you're talking about Coresight ETM.

> Greg has some comments on our implementation and doesn't advocate
> to build driver on debugfs [1]. So I resend this series to
> collect more feedbacks on the implementation of this driver.
>
> Hi perf and ETM related experts, is it suggested to adapt this driver
> to perf? Or is the debugfs approach acceptable? Otherwise use

Aside from the above, I don't think the use of debugfs for kernel ABIs
is ever encouraged.

Regards,
--
Ale

WARNING: multiple messages have this Message-ID (diff)
From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Yicong Yang <yangyicong@hisilicon.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org,
	linux-pci@vger.kernel.org
Cc: helgaas@kernel.org, gregkh@linuxfoundation.org,
	lorenzo.pieralisi@arm.com, will@kernel.org, mark.rutland@arm.com,
	mathieu.poirier@linaro.org, suzuki.poulose@arm.com,
	mike.leach@linaro.org, leo.yan@linaro.org,
	jonathan.cameron@huawei.com, song.bao.hua@hisilicon.com,
	john.garry@huawei.com, prime.zeng@huawei.com,
	liuqi115@huawei.com, zhangshaokun@hisilicon.com,
	yangyicong@hisilicon.com, linuxarm@huawei.com,
	alexander.shishkin@linux.intel.com
Subject: Re: [PATCH RESEND 0/4] Add support for HiSilicon PCIe Tune and Trace device
Date: Sat, 17 Apr 2021 16:56:35 +0300	[thread overview]
Message-ID: <8735vpf20c.fsf@ashishki-desk.ger.corp.intel.com> (raw)
In-Reply-To: <1618654631-42454-1-git-send-email-yangyicong@hisilicon.com>

Yicong Yang <yangyicong@hisilicon.com> writes:

> The reason for not using perf is because there is no current support
> for uncore tracing in the perf facilities.

Not unless you count

$ perf list|grep -ic uncore
77

> We have our own format
> of data and don't need perf doing the parsing.

Perf has AUX buffers, which are used for all kinds of own formats.

> A similar approach for implementing this function is ETM, which use
> sysfs for configuring and a character device for dumping data.

And also perf. One reason ETM has a sysfs interface is because the
driver predates perf's AUX buffers. Can't say if it's the only
reason. I'm assuming you're talking about Coresight ETM.

> Greg has some comments on our implementation and doesn't advocate
> to build driver on debugfs [1]. So I resend this series to
> collect more feedbacks on the implementation of this driver.
>
> Hi perf and ETM related experts, is it suggested to adapt this driver
> to perf? Or is the debugfs approach acceptable? Otherwise use

Aside from the above, I don't think the use of debugfs for kernel ABIs
is ever encouraged.

Regards,
--
Ale

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2021-04-17 13:56 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-17 10:17 [PATCH RESEND 0/4] Add support for HiSilicon PCIe Tune and Trace device Yicong Yang
2021-04-17 10:17 ` Yicong Yang
2021-04-17 10:17 ` [PATCH RESEND 1/4] hwtracing: Add trace function " Yicong Yang
2021-04-17 10:17   ` Yicong Yang
2021-04-17 10:17 ` [PATCH RESEND 2/4] hwtracing: Add tune " Yicong Yang
2021-04-17 10:17   ` Yicong Yang
2021-04-17 10:17 ` [PATCH RESEND 3/4] docs: Add HiSilicon PTT device driver documentation Yicong Yang
2021-04-17 10:17   ` Yicong Yang
2021-04-19  9:07   ` Daniel Thompson
2021-04-19  9:07     ` Daniel Thompson
2021-04-19 13:12     ` Yicong Yang
2021-04-19 13:12       ` Yicong Yang
2021-04-17 10:17 ` [PATCH RESEND 4/4] MAINTAINERS: Add maintainer for HiSilicon PTT driver Yicong Yang
2021-04-17 10:17   ` Yicong Yang
2021-04-17 13:56 ` Alexander Shishkin [this message]
2021-04-17 13:56   ` [PATCH RESEND 0/4] Add support for HiSilicon PCIe Tune and Trace device Alexander Shishkin
2021-04-19 13:03   ` Yicong Yang
2021-04-19 13:03     ` Yicong Yang
2021-04-22  3:49     ` Leo Yan
2021-04-22  3:49       ` Leo Yan
2021-04-22 12:54       ` Yicong Yang
2021-04-22 12:54         ` Yicong Yang
2021-04-19 11:17 ` Suzuki K Poulose
2021-04-19 11:17   ` Suzuki K Poulose
2021-04-19 13:21   ` Yicong Yang
2021-04-19 13:21     ` Yicong Yang
2021-04-19 16:11     ` Suzuki K Poulose
2021-04-19 16:11       ` Suzuki K Poulose

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