Re: [PATCH v3] lib: add size unit t/p/e to memparse

[Andrew Morton]

On Wed, 2 Apr 2014 16:54:37 +0800 Gui Hecheng <guihc.fnst@xxxxxxxxxxxxxx> wrote:

> For modern filesystems such as btrfs, t/p/e size level operations
> are common.
> add size unit t/p/e parsing to memparse
> 
> Signed-off-by: Gui Hecheng <guihc.fnst@xxxxxxxxxxxxxx>
> ---
> changelog
> 	v1->v2: replace kilobyte with kibibyte, and others
> 	v2->v3: add missing unit "bytes" in comment
> ---
>  lib/cmdline.c | 25 ++++++++++++++++++++-----
>  1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/cmdline.c b/lib/cmdline.c
> index eb67911..511b9be 100644
> --- a/lib/cmdline.c
> +++ b/lib/cmdline.c
> @@ -119,11 +119,17 @@ char *get_options(const char *str, int nints, int *ints)
>   *	@retptr: (output) Optional pointer to next char after parse completes
>   *
>   *	Parses a string into a number.  The number stored at @ptr is
> - *	potentially suffixed with %K (for kilobytes, or 1024 bytes),
> - *	%M (for megabytes, or 1048576 bytes), or %G (for gigabytes, or
> - *	1073741824).  If the number is suffixed with K, M, or G, then
> - *	the return value is the number multiplied by one kilobyte, one
> - *	megabyte, or one gigabyte, respectively.
> + *	potentially suffixed with
> + *	%K (for kibibytes, or 1024 bytes),
> + *	%M (for mebibytes, or 1048576 bytes),
> + *	%G (for gibibytes, or 1073741824 bytes),
> + *	%T (for tebibytes, or 1099511627776 bytes),
> + *	%P (for pebibytes, or 1125899906842624 bytes),
> + *	%E (for exbibytes, or 1152921504606846976 bytes).

I'm afraid I find these names quite idiotic - we all know what the
traditional terms mean so why go and muck with it.

Also, kibibytes sounds like cat food.

> @@ -133,6 +139,15 @@ unsigned long long memparse(const char *ptr, char **retptr)
>  	unsigned long long ret = simple_strtoull(ptr, &endptr, 0);
>  
>  	switch (*endptr) {
> +	case 'E':
> +	case 'e':
> +		ret <<= 10;
> +	case 'P':
> +	case 'p':
> +		ret <<= 10;
> +	case 'T':
> +	case 't':
> +		ret <<= 10;
>  	case 'G':
>  	case 'g':
>  		ret <<= 10;

That bit makes sense.
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