[V6,02/17] io_uring: use ctx->cached_sq_head to calculate left sqes
Commit Message
Use ctx->cached_sq_head to calculate 'left' sqes, and prepare for supporting
fused requests, which need to get req/sqe in its own ->prep() callback.
ctx->cached_sq_head should always be cached or to be fetched, so this change
is just fine.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
io_uring/io_uring.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
@@ -2429,15 +2429,16 @@ int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
__must_hold(&ctx->uring_lock)
{
unsigned int entries = io_sqring_entries(ctx);
- unsigned int left;
+ unsigned old_head = ctx->cached_sq_head;
+ unsigned int left = 0;
int ret;
if (unlikely(!entries))
return 0;
/* make sure SQ entry isn't read before tail */
- ret = left = min3(nr, ctx->sq_entries, entries);
- io_get_task_refs(left);
- io_submit_state_start(&ctx->submit_state, left);
+ ret = min3(nr, ctx->sq_entries, entries);
+ io_get_task_refs(ret);
+ io_submit_state_start(&ctx->submit_state, ret);
do {
const struct io_uring_sqe *sqe;
@@ -2456,11 +2457,12 @@ int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
*/
if (unlikely(io_submit_sqe(ctx, req, sqe)) &&
!(ctx->flags & IORING_SETUP_SUBMIT_ALL)) {
- left--;
+ left = 1;
break;
}
- } while (--left);
+ } while ((ctx->cached_sq_head - old_head) < ret);
+ left = ret - (ctx->cached_sq_head - old_head) - left;
if (unlikely(left)) {
ret -= left;
/* try again if it submitted nothing and can't allocate a req */