| Message ID | 6d1f598e27d623c07fc49d6baee13089a9b1216c.1743848241.git.asml.silence@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/1] io_uring/zcrx: put refill data into separate cache line | expand |
On Sat, 05 Apr 2025 11:17:49 +0100, Pavel Begunkov wrote: > Refill queue lock and other bits are only used from the allocation path > on the rx softirq side, but it shares the cache line with other fields > like ctx that are used also in the "syscall" path, which causes cache > bouncing when softirq runs on a different CPU. > > Separate them into different cache lines. The first one now contains > constant fields used by both contextx, followed by a line responsible > for refill queue data. > > [...] Applied, thanks! [1/1] io_uring/zcrx: put refill data into separate cache line (no commit info) Best regards,
diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h index 706cc7300780..b59c560d5d84 100644 --- a/io_uring/zcrx.h +++ b/io_uring/zcrx.h @@ -26,11 +26,11 @@ struct io_zcrx_ifq { struct io_ring_ctx *ctx; struct io_zcrx_area *area; + spinlock_t rq_lock ____cacheline_aligned_in_smp; struct io_uring *rq_ring; struct io_uring_zcrx_rqe *rqes; - u32 rq_entries; u32 cached_rq_head; - spinlock_t rq_lock; + u32 rq_entries; u32 if_rxq; struct device *dev;
Refill queue lock and other bits are only used from the allocation path on the rx softirq side, but it shares the cache line with other fields like ctx that are used also in the "syscall" path, which causes cache bouncing when softirq runs on a different CPU. Separate them into different cache lines. The first one now contains constant fields used by both contextx, followed by a line responsible for refill queue data. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> --- io_uring/zcrx.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)