Re: [PATCH V2 15/19] selftests/resctrl: Change return type of umount_resctrlfs() to void

From: Reinette Chatre <reinette.chatre@intel.com>
To: "Prakhya, Sai Praneeth" <sai.praneeth.prakhya@intel.com>,
	"shuah@kernel.org" <shuah@kernel.org>,
	"skhan@linuxfoundation.org" <skhan@linuxfoundation.org>,
	"linux-kselftest@vger.kernel.org"
	<linux-kselftest@vger.kernel.org>
Cc: "tglx@linutronix.de" <tglx@linutronix.de>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"bp@alien8.de" <bp@alien8.de>, "Luck, Tony" <tony.luck@intel.com>,
	"babu.moger@amd.com" <babu.moger@amd.com>,
	"james.morse@arm.com" <james.morse@arm.com>,
	"Shankar, Ravi V" <ravi.v.shankar@intel.com>,
	"Yu, Fenghua" <fenghua.yu@intel.com>,
	"x86@kernel.org" <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"dan.carpenter@oracle.com" <dan.carpenter@oracle.com>,
	"dcb314@hotmail.com" <dcb314@hotmail.com>
Subject: Re: [PATCH V2 15/19] selftests/resctrl: Change return type of umount_resctrlfs() to void
Date: Thu, 21 May 2020 11:15:15 -0700	[thread overview]
Message-ID: <2e9ea256-cbf4-8222-c639-74479400fd77@intel.com> (raw)
In-Reply-To: <FFF73D592F13FD46B8700F0A279B802F573B66AE@ORSMSX114.amr.corp.intel.com>

Hi Sai,

On 5/21/2020 10:19 AM, Prakhya, Sai Praneeth wrote:
> Hi Reinette,
> 
>> -----Original Message-----
>> From: Reinette Chatre <reinette.chatre@intel.com>
>> Sent: Wednesday, May 20, 2020 4:52 PM
>> To: Prakhya, Sai Praneeth <sai.praneeth.prakhya@intel.com>;
>> shuah@kernel.org; skhan@linuxfoundation.org; linux-kselftest@vger.kernel.org
>> Cc: tglx@linutronix.de; mingo@redhat.com; bp@alien8.de; Luck, Tony
>> <tony.luck@intel.com>; babu.moger@amd.com; james.morse@arm.com;
>> Shankar, Ravi V <ravi.v.shankar@intel.com>; Yu, Fenghua
>> <fenghua.yu@intel.com>; x86@kernel.org; linux-kernel@vger.kernel;
>> dan.carpenter@oracle.com; dcb314@hotmail.com
>> Subject: Re: [PATCH V2 15/19] selftests/resctrl: Change return type of
>> umount_resctrlfs() to void
>>
>> Hi Sai,
>>
>> On 5/18/2020 3:08 PM, Sai Praneeth Prakhya wrote:
>>> umount_resctrlfs() is used only during tear down path and there is
>>> nothing much to do if unmount of resctrl file system fails, so, all
>>> the callers of this function are not checking for the return value.
>>> Hence, change the return type of this function from int to void.
>>
>> Should the callers be ignoring the return value? From what I can tell the
>> filesystem is unmounted between test runs so I wonder if it may help if the
>> return code is used and the test exits with an appropriate error to user space for
>> possible investigation instead of attempting to run a new test on top of the
>> resctrl filesystem that could potentially be having issues at the time.
> 
> Makes sense to me to check for the return value of umount() and take appropriate
> action rather than ignoring it. But, since this might happen very rarely (I haven't
> noticed umount() failing till now), I am thinking to queue this up for cleanup series.
> What do you think?

That sounds good.

> 
> This bug fixes series will then have patches 16 and 17 because they are fixing a bug
> that could be easily noticed. Please let me know if you think otherwise.

I don't, dropping this change that makes it easy to ignore an error in
this round so that any errors could be dealt with better in a later
patch sounds good to me.

Thank you

Reinette