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From: Will Deacon <will@kernel.org>
To: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Dong Aisheng <aisheng.dong@nxp.com>, Frank Li <frank.li@nxp.com>,
	Joakim Zhang <qiangqing.zhang@nxp.com>,
	linux-imx@nxp.com, kernel@pengutronix.de,
	Fabio Estevam <fabio.estevam@nxp.com>,
	Shawn Guo <shawnguo@kernel.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] perf/imx_ddr: Fix leaking cpuhp_state
Date: Tue, 14 Jan 2020 16:51:48 +0000	[thread overview]
Message-ID: <20200114165142.GE2579@willie-the-truck> (raw)
In-Reply-To: <3cff630697d76d24d4ab93dfcddc978d84b8f2d8.1576711200.git.leonard.crestez@nxp.com>

On Thu, Dec 19, 2019 at 01:20:19AM +0200, Leonard Crestez wrote:
> This driver allocates a dynamic cpu hotplug state but never releases it.
> If reloaded in a loop it will quickly trigger a WARN message:
> 
> 	"No more dynamic states available for CPU hotplug"
> 
> Fix by calling cpuhp_remove_multi_state like several other perf pmu
> drivers.
> 
> Fixes: 8f4c58ae59f5 ("perf/imx_ddr: Fix leaking cpuhp_state")
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  drivers/perf/fsl_imx8_ddr_perf.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
> index 3be61be1ba91..aa30ca5f6b29 100644
> --- a/drivers/perf/fsl_imx8_ddr_perf.c
> +++ b/drivers/perf/fsl_imx8_ddr_perf.c
> @@ -672,12 +672,14 @@ static int ddr_perf_probe(struct platform_device *pdev)
>  		goto ddr_perf_err;
>  
>  	return 0;
>  
>  ddr_perf_err:
> -	if (pmu->cpuhp_state)
> +	if (pmu->cpuhp_state) {
>  		cpuhp_state_remove_instance_nocalls(pmu->cpuhp_state, &pmu->node);
> +		cpuhp_remove_multi_state(pmu->cpuhp_state);
> +	}

Shouldn't we also be checking the return value of the earlier call to
cpuhp_state_add_instant_nocalls() and then calling only
cpuhp_remove_multi_state() if it fails?

Thanks,

Will

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      parent reply	other threads:[~2020-01-14 16:52 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-18 23:20 [PATCH] perf/imx_ddr: Fix leaking cpuhp_state Leonard Crestez
2020-01-13 20:00 ` Leonard Crestez
2020-01-14 16:51 ` Will Deacon [this message]

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