Re: [LSF/MM TOPIC] Improve performance of fget/fput

[Matthew Wilcox]

On Fri, Feb 15, 2019 at 04:38:05PM +0000, Dave Watson wrote:
> There might also be ways to rearrange the file* struct or fd table so
> that we're not taking so many cache misses for sockfd_lookup_light,
> since for sockets we don't use most of the file* struct at all.

I don't think there's too much opportunity to rearrange the fd table.
We go from task_struct->files_struct->fdtable->fd[i].  I have a plan
to use the Maple Tree data structure I'm currently working on to change
that to task_struct->files_struct->maple_node->fd[i], but it'll be
the same number of cache misses.