From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cpufreq: speedstep: remove unnecessary static in speedstep_detect_chipset()
Date: Sat, 22 Jul 2017 00:38:22 +0200 [thread overview]
Message-ID: <1908499.SpSD1enk2O@aspire.rjw.lan> (raw)
In-Reply-To: <20170705030921.GA18166@embeddedgus>
On Tuesday, July 04, 2017 10:09:21 PM Gustavo A. R. Silva wrote:
> Remove unnecessary static on local variable hostbridge.
> Such variable is initialized before being used,
> on every execution path throughout the function.
> The static has no benefit and, removing it reduces
> the code size.
>
> This issue was detected using Coccinelle and the following semantic patch:
>
> @bad exists@
> position p;
> identifier x;
> type T;
> @@
>
> static T x@p;
> ...
> x = <+...x...+>
>
> @@
> identifier x;
> expression e;
> type T;
> position p != bad.p;
> @@
>
> -static
> T x@p;
> ... when != x
> when strict
> ?x = e;
>
> In the following log you can see the difference in the code size. Also,
> there is a significant difference in the bss segment. This log is the
> output of the size command, before and after the code change:
>
> before:
> text data bss dec hex filename
> 5084 3392 256 8732 221c drivers/cpufreq/speedstep-ich.o
>
> after:
> text data bss dec hex filename
> 5062 3304 192 8558 216e drivers/cpufreq/speedstep-ich.o
>
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
> drivers/cpufreq/speedstep-ich.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/speedstep-ich.c b/drivers/cpufreq/speedstep-ich.c
> index b86953a..0412a24 100644
> --- a/drivers/cpufreq/speedstep-ich.c
> +++ b/drivers/cpufreq/speedstep-ich.c
> @@ -207,7 +207,7 @@ static unsigned int speedstep_detect_chipset(void)
> * 8100 which use a pretty old revision of the 82815
> * host bridge. Abort on these systems.
> */
> - static struct pci_dev *hostbridge;
> + struct pci_dev *hostbridge;
>
> hostbridge = pci_get_subsys(PCI_VENDOR_ID_INTEL,
> PCI_DEVICE_ID_INTEL_82815_MC,
>
Applied, thanks!
prev parent reply other threads:[~2017-07-21 22:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-05 3:09 [PATCH] cpufreq: speedstep: remove unnecessary static in speedstep_detect_chipset() Gustavo A. R. Silva
2017-07-05 3:53 ` Viresh Kumar
2017-07-05 10:14 ` Dominik Brodowski
2017-07-21 22:38 ` Rafael J. Wysocki [this message]
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