[PATCH] perf/imx_ddr: Fix leaking cpuhp_state

Will Deacon will at kernel.org
Tue Jan 14 08:51:48 PST 2020


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 at 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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