io_uring: batch completion in prior_task_list

In previous patches, we have already gathered some tw with
io_req_task_complete() as callback in prior_task_list, let's complete
them in batch while we cannot grab uring lock. In this way, we batch
the req_complete_post path.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20211208052125.351587-1-haoxu@linux.alibaba.com
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Hao Xu 2021-12-08 13:21:25 +08:00 committed by Jens Axboe
parent a37fae8aaa
commit f28c240e71

View File

@ -2225,7 +2225,49 @@ static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
percpu_ref_put(&ctx->refs);
}
static void handle_tw_list(struct io_wq_work_node *node, struct io_ring_ctx **ctx, bool *locked)
static inline void ctx_commit_and_unlock(struct io_ring_ctx *ctx)
{
io_commit_cqring(ctx);
spin_unlock(&ctx->completion_lock);
io_cqring_ev_posted(ctx);
}
static void handle_prev_tw_list(struct io_wq_work_node *node,
struct io_ring_ctx **ctx, bool *uring_locked)
{
if (*ctx && !*uring_locked)
spin_lock(&(*ctx)->completion_lock);
do {
struct io_wq_work_node *next = node->next;
struct io_kiocb *req = container_of(node, struct io_kiocb,
io_task_work.node);
if (req->ctx != *ctx) {
if (unlikely(!*uring_locked && *ctx))
ctx_commit_and_unlock(*ctx);
ctx_flush_and_put(*ctx, uring_locked);
*ctx = req->ctx;
/* if not contended, grab and improve batching */
*uring_locked = mutex_trylock(&(*ctx)->uring_lock);
percpu_ref_get(&(*ctx)->refs);
if (unlikely(!*uring_locked))
spin_lock(&(*ctx)->completion_lock);
}
if (likely(*uring_locked))
req->io_task_work.func(req, uring_locked);
else
__io_req_complete_post(req, req->result, io_put_kbuf(req));
node = next;
} while (node);
if (unlikely(!*uring_locked))
ctx_commit_and_unlock(*ctx);
}
static void handle_tw_list(struct io_wq_work_node *node,
struct io_ring_ctx **ctx, bool *locked)
{
do {
struct io_wq_work_node *next = node->next;
@ -2246,31 +2288,38 @@ static void handle_tw_list(struct io_wq_work_node *node, struct io_ring_ctx **ct
static void tctx_task_work(struct callback_head *cb)
{
bool locked = false;
bool uring_locked = false;
struct io_ring_ctx *ctx = NULL;
struct io_uring_task *tctx = container_of(cb, struct io_uring_task,
task_work);
while (1) {
struct io_wq_work_node *node;
struct io_wq_work_node *node1, *node2;
if (!tctx->prior_task_list.first &&
!tctx->task_list.first && locked)
if (!tctx->task_list.first &&
!tctx->prior_task_list.first && uring_locked)
io_submit_flush_completions(ctx);
spin_lock_irq(&tctx->task_lock);
node= wq_list_merge(&tctx->prior_task_list, &tctx->task_list);
if (!node)
node1 = tctx->prior_task_list.first;
node2 = tctx->task_list.first;
INIT_WQ_LIST(&tctx->task_list);
INIT_WQ_LIST(&tctx->prior_task_list);
if (!node2 && !node1)
tctx->task_running = false;
spin_unlock_irq(&tctx->task_lock);
if (!node)
if (!node2 && !node1)
break;
handle_tw_list(node, &ctx, &locked);
if (node1)
handle_prev_tw_list(node1, &ctx, &uring_locked);
if (node2)
handle_tw_list(node2, &ctx, &uring_locked);
cond_resched();
}
ctx_flush_and_put(ctx, &locked);
ctx_flush_and_put(ctx, &uring_locked);
}
static void io_req_task_work_add(struct io_kiocb *req, bool priority)
@ -2759,7 +2808,7 @@ static void io_complete_rw(struct kiocb *kiocb, long res)
return;
req->result = res;
req->io_task_work.func = io_req_task_complete;
io_req_task_work_add(req, true);
io_req_task_work_add(req, !!(req->ctx->flags & IORING_SETUP_SQPOLL));
}
static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)