From c92fcfc2bab54451c4f1481755ea244f413455cb Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 2 Jun 2023 08:41:46 -0600 Subject: [PATCH] io_uring: avoid indirect function calls for the hottest task_work We use task_work for a variety of reasons, but doing completions or triggering rety after poll are by far the hottest two. Use the indirect funtion call wrappers to avoid the indirect function call if CONFIG_RETPOLINE is set. Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 9 +++++++-- io_uring/poll.c | 2 +- io_uring/poll.h | 2 ++ io_uring/rw.c | 2 +- io_uring/rw.h | 1 + 5 files changed, 12 insertions(+), 4 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index c99a7a0..fc511cb 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -95,6 +95,7 @@ #include "timeout.h" #include "poll.h" +#include "rw.h" #include "alloc_cache.h" #define IORING_MAX_ENTRIES 32768 @@ -1205,7 +1206,9 @@ static unsigned int handle_tw_list(struct llist_node *node, ts->locked = mutex_trylock(&(*ctx)->uring_lock); percpu_ref_get(&(*ctx)->refs); } - req->io_task_work.func(req, ts); + INDIRECT_CALL_2(req->io_task_work.func, + io_poll_task_func, io_req_rw_complete, + req, ts); node = next; count++; if (unlikely(need_resched())) { @@ -1415,7 +1418,9 @@ again: struct io_kiocb *req = container_of(node, struct io_kiocb, io_task_work.node); prefetch(container_of(next, struct io_kiocb, io_task_work.node)); - req->io_task_work.func(req, ts); + INDIRECT_CALL_2(req->io_task_work.func, + io_poll_task_func, io_req_rw_complete, + req, ts); ret++; node = next; } diff --git a/io_uring/poll.c b/io_uring/poll.c index c90e47d..9689806 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -326,7 +326,7 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts) return IOU_POLL_NO_ACTION; } -static void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts) +void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts) { int ret; diff --git a/io_uring/poll.h b/io_uring/poll.h index b2393b4..ff4d5d7 100644 --- a/io_uring/poll.h +++ b/io_uring/poll.h @@ -38,3 +38,5 @@ bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk, bool cancel_all); void io_apoll_cache_free(struct io_cache_entry *entry); + +void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts); diff --git a/io_uring/rw.c b/io_uring/rw.c index 3f118ed..c23d8ba 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -283,7 +283,7 @@ static inline int io_fixup_rw_res(struct io_kiocb *req, long res) return res; } -static void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts) +void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts) { io_req_io_end(req); diff --git a/io_uring/rw.h b/io_uring/rw.h index 3b733f4..4b89f96 100644 --- a/io_uring/rw.h +++ b/io_uring/rw.h @@ -22,3 +22,4 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags); int io_writev_prep_async(struct io_kiocb *req); void io_readv_writev_cleanup(struct io_kiocb *req); void io_rw_fail(struct io_kiocb *req); +void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts); -- 2.7.4