On Tue, 10 Jan 2017, Vikas Shivappa wrote:
> + * @display_str: Format string to show schemata
> + * @validate: API to validate the ctrl values.
> * @info_files: resctrl info files for the resource
> * @infofiles_len: Number of info files
> * @max_delay: Max throttle delay
> @@ -99,6 +101,9 @@ struct rdt_resource {
> int cbm_len;
> int min_cbm_bits;
> u32 no_ctrl;
> + char *display_str;
> + int (*validate) (char *buf, unsigned long *data,
> + struct rdt_resource *r);
Again this display and validation change wants to be seperate from the
bandwidth stuff.
It's not rocket science to split patches into preparatory and
implementation parts.
> + r->display_str = kstrdup("%d=%d", GFP_KERNEL);
> + if (!r->display_str)
> + return -ENOMEM;
And the point of this allocation is? To consume extra memory for a constant
string which is in const data anyway.
r->display_str = "%d=%d";
does not need allcotion and consumes exactly the same amount of const data
as the above. Oh well...
> -static inline bool get_rdt_resources(void)
> +static inline int get_rdt_resources(void)
> {
And the point of this change is? Lots of churn to return the same -ENODEV
value at the call site. So why are you trying to return other values
instead of the simple boolean success/fail decision?
> /*
> + * Check whether MBE 'throttle by' value is correct.
> + * As per the SDM, when the scale is linear the
> + * throttle_by granularity is '100 - max_thrtl_by'
> + * and when its non-linear it is 'power of 2'.
That's wrong. We really want to let the user set a bandwidth percentage
value from 0 - 100 %. And then adjust it to the proper value which the
hardware can provide. So the user value is independent from granularity,
linear and the max throttling allowed.
> /*
> - * Read one cache bit mask (hex). Check that it is valid for the current
> - * resource type.
> + * Read the user RDT control value into tempory buffer:
> + * Cache bit mask (hex) or Memory b/w throttle (decimal).
> + * Check that it is valid for the current resource type.
> */
> -static int parse_cbm(char *buf, struct rdt_resource *r)
> +static int parse_ctrls(char *buf, struct rdt_resource *r)
> {
> unsigned long data;
> - int ret;
> + int ret = 0;
What's the purpose of initializing ret to 0 if the next action is assigning
ret the return value of the validate function?
> - ret = kstrtoul(buf, 16, &data);
> - if (ret)
> - return ret;
> - if (!cbm_validate(data, r))
> - return -EINVAL;
> + ret = r->validate(buf, &data, r);
> r->tmp_ctrl[r->num_tmp_ctrl++] = data;
>
> - return 0;
> + return ret;
> }
Thanks,
tglx
