We cache multishot CQEs before flushing them to the CQ in
submit_state.cqe. It's a 16 entry cache totalling 256 bytes in the
middle of the io_submit_state structure. Move it out of there, it
should help with CPU caches for the submission state, and shouldn't
affect cached CQEs.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
include/linux/io_uring_types.h | 3 ++-
io_uring/io_uring.c | 6 +++---
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 5de5dffe29df..01bdbc223edd 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -176,7 +176,6 @@ struct io_submit_state {
unsigned short submit_nr;
unsigned int cqes_count;
struct blk_plug plug;
- struct io_uring_cqe cqes[16];
};
struct io_ev_fd {
@@ -307,6 +306,8 @@ struct io_ring_ctx {
unsigned cq_last_tm_flush;
} ____cacheline_aligned_in_smp;
+ struct io_uring_cqe completion_cqes[16];
+
/* IRQ completion list, under ->completion_lock */
struct io_wq_work_list locked_free_list;
unsigned int locked_free_nr;
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index a6eea3938802..88599852af82 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -880,7 +880,7 @@ static void __io_flush_post_cqes(struct io_ring_ctx *ctx)
lockdep_assert_held(&ctx->uring_lock);
for (i = 0; i < state->cqes_count; i++) {
- struct io_uring_cqe *cqe = &state->cqes[i];
+ struct io_uring_cqe *cqe = &ctx->completion_cqes[i];
if (!io_fill_cqe_aux(ctx, cqe->user_data, cqe->res, cqe->flags)) {
if (ctx->task_complete) {
@@ -931,7 +931,7 @@ bool io_fill_cqe_req_aux(struct io_kiocb *req, bool defer, s32 res, u32 cflags)
lockdep_assert_held(&ctx->uring_lock);
- if (ctx->submit_state.cqes_count == ARRAY_SIZE(ctx->submit_state.cqes)) {
+ if (ctx->submit_state.cqes_count == ARRAY_SIZE(ctx->completion_cqes)) {
__io_cq_lock(ctx);
__io_flush_post_cqes(ctx);
/* no need to flush - flush is deferred */
@@ -945,7 +945,7 @@ bool io_fill_cqe_req_aux(struct io_kiocb *req, bool defer, s32 res, u32 cflags)
if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq))
return false;
- cqe = &ctx->submit_state.cqes[ctx->submit_state.cqes_count++];
+ cqe = &ctx->completion_cqes[ctx->submit_state.cqes_count++];
cqe->user_data = user_data;
cqe->res = res;
cqe->flags = cflags;
--
2.41.0
