Re: [PATCH v2 1/8] lib/printbuf: New data structure for heap-allocated strings

Joe Perches
2022-04-24T23:56:03Z

On Thu, 2022-04-21 at 19:48 -0400, Kent Overstreet wrote:
> This adds printbufs: simple heap-allocated strings meant for building up
> structured messages, for logging/procfs/sysfs and elsewhere. They've
> been heavily used in bcachefs for writing .to_text() functions/methods -
> pretty printers, which has in turn greatly improved the overall quality
> of error messages.
>
> Basic usage is documented in include/linux/printbuf.h.

Given the maximum printk output is less than 1024 bytes, why should
this be allowed to be larger than that or larger than PAGE_SIZE?

> + * pr_human_readable_u64, pr_human_readable_s64: Print an integer with human
> + * readable units.

Why not extend vsprintf for this using something like %pH[8|16|32|64]
or %pH[c|s|l|ll|uc|us|ul|ull] ?