Queues heads and tails cache line aligned. That makes sq, cq taking 4
lines or 5 lines if we include the rest of struct io_rings (e.g.
sq_flags is frequently accessed).
Since modern io_uring is mostly single threaded, it doesn't make much
send to spread them as such, it wastes space and puts additional pressure
on caches. Put them all into a single line.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
include/linux/io_uring_types.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index c0c03d8059df..608a8e80e881 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -69,8 +69,8 @@ struct io_uring_task {
};
struct io_uring {
- u32 head ____cacheline_aligned_in_smp;
- u32 tail ____cacheline_aligned_in_smp;
+ u32 head;
+ u32 tail;
};
/*
--
2.41.0
