Re: [PATCH] fs: optimise generic_write_check_limits()

[Al Viro]

On Fri, Aug 06, 2021 at 12:22:10PM +0100, Pavel Begunkov wrote:
> Even though ->s_maxbytes is used by generic_write_check_limits() only in
> case of O_LARGEFILE, the value is loaded unconditionally, which is heavy
> and takes 4 indirect loads. Optimise it by not touching ->s_maxbytes,
> if it's not going to be used.

Out of curiosity - how much of improvement have you actually seen on that?
I can't say I hate the patch, but I'd like to see the data...