From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Viresh Kumar <viresh.kumar@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Vincent Guittot <vincent.guittot@linaro.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [PATCH 3/4] base/drivers/topology: Move instructions in the error path
Date: Tue, 30 Oct 2018 09:32:44 +0100 [thread overview]
Message-ID: <340a6999-2281-2eaf-5a83-b1a0898a2ab5@linaro.org> (raw)
In-Reply-To: <CAOh2x==N=YM+4WE8wouM9mFd0h0L+npwww97e2HAf2HsEm5J0w@mail.gmail.com>
On 30/10/2018 07:12, Viresh Kumar wrote:
> On Mon, Oct 29, 2018 at 9:56 PM Daniel Lezcano
> <daniel.lezcano@linaro.org> wrote:
>>
>> When the function topology_parse_cpu_capacity() fails, we set the boolean
>> cap_parsing_failed to true and we free the raw_capacity. This is correct as
>> the function begins with a check against cap_parsing_failed thus protecting
>> the function to be re-entered.
>>
>> However, even it is impossible that can happen with the current code, let's
>
> Why impossible ?
>> move in the instructions:
>>
>> - cap_parsing_failed = true;
>> - free_raw_capacity();
>>
>> ... in the 'else' block when the error is detected, that is more semantically
>> correct.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>> ---
>> drivers/base/arch_topology.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
>> index b19d6d4..7311641 100644
>> --- a/drivers/base/arch_topology.c
>> +++ b/drivers/base/arch_topology.c
>> @@ -155,9 +155,9 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
>> pr_err("cpu_capacity: missing %pOF raw capacity\n",
>> cpu_node);
>> pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
>> + cap_parsing_failed = true;
>> + free_raw_capacity();
>> }
>> - cap_parsing_failed = true;
>> - free_raw_capacity();
>
> While it is fine to move free_raw_capacity(), it is not to move the
> other line. With your
> patch what will happen if the first CPU in DT doesn't have the
> "capacity-dmips-mhz"
> property set ? We will never set cap_parsing_failed and keep on
> re-entering this routine
> which wasn't required.
Ok.
--
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next prev parent reply other threads:[~2018-10-30 8:32 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-29 16:23 [PATCH 1/4] base/drivers/arch_topology: Remove useless check Daniel Lezcano
2018-10-29 16:23 ` [PATCH 2/4] base/drivers/arch_topology: Replace mutex with READ_ONCE / WRITE_ONCE Daniel Lezcano
2018-10-30 5:57 ` Viresh Kumar
2018-11-23 13:58 ` Sudeep Holla
2018-11-23 16:04 ` Daniel Lezcano
2018-11-23 16:20 ` Sudeep Holla
2018-11-23 16:54 ` Daniel Lezcano
2018-11-26 8:27 ` Juri Lelli
2018-11-26 8:39 ` Daniel Lezcano
2018-11-26 11:33 ` Mark Brown
2018-10-29 16:23 ` [PATCH 3/4] base/drivers/topology: Move instructions in the error path Daniel Lezcano
2018-10-30 6:12 ` Viresh Kumar
2018-10-30 8:32 ` Daniel Lezcano [this message]
2018-10-29 16:23 ` [PATCH 4/4] base/drivers/topology: Default dmpis-mhz if they are not set in DT Daniel Lezcano
2018-10-30 7:13 ` Viresh Kumar
2018-10-30 8:39 ` Daniel Lezcano
2018-10-30 8:45 ` Viresh Kumar
2018-10-30 8:58 ` Viresh Kumar
2018-11-21 22:12 ` Daniel Lezcano
2018-11-22 4:29 ` Viresh Kumar
2018-11-22 10:29 ` Daniel Lezcano
2018-11-22 10:31 ` Viresh Kumar
2018-11-22 10:32 ` Daniel Lezcano
2018-11-22 11:11 ` Daniel Lezcano
2018-10-30 5:50 ` [PATCH 1/4] base/drivers/arch_topology: Remove useless check Viresh Kumar
2018-10-30 7:55 ` Daniel Lezcano
2018-10-30 8:33 ` Viresh Kumar
2018-10-30 13:35 ` Daniel Lezcano
2018-10-31 4:27 ` Viresh Kumar
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