Re: [patch 20/24] perfmon: system calls interface

[Ingo Molnar <mingo@elte.hu>]

* eranian@googlemail.com <eranian@googlemail.com> wrote:

> +
> +/*
> + * unlike the other perfmon system calls, this one returns a file descriptor
> + * or a value < 0 in case of error, very much like open() or socket()
> + */
> +asmlinkage long sys_pfm_create(int flags, struct pfarg_sinfo __user *ureq)
> +{
> +	struct pfm_context *new_ctx;
> +	struct pfarg_sinfo sif;
> +	int ret;
> +
> +	PFM_DBG("flags=0x%x sif=%p", flags, ureq);
> +
> +	if (perfmon_disabled)
> +		return -ENOSYS;
> +
> +	if (flags) {
> +		PFM_DBG("no flags accepted yet");
> +		return -EINVAL;

the canonical return code for non-yet-supported flags is not -EINVAL 
but -ENOSYS.

	Ingo