io_uring: reduce/pack size of io_ring_ctx
With the recent flurry of additions and changes to io_uring, the
layout of io_ring_ctx has become a bit stale. We're right now at
704 bytes in size on my x86-64 build, or 11 cachelines. This
patch does two things:
- We have to completion structs embedded, that we only use for
quiesce of the ctx (or shutdown) and for sqthread init cases.
That 2x32 bytes right there, let's dynamically allocate them.
- Reorder the struct a bit with an eye on cachelines, use cases,
and holes.
With this patch, we're down to 512 bytes, or 8 cachelines.
Reviewed-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 file changed