io_uring/napi: clean up __io_napi_do_busy_loop

__io_napi_do_busy_loop now requires to have loop_end in its parameters.
This makes the code cleaner and also has the benefit of removing a
branch since the only caller not passing NULL for loop_end_arg is also
setting the value conditionally.

Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Link: https://lore.kernel.org/r/d5b9bb91b1a08fff50525e1c18d7b4709b9ca100.1728828877.git.olivier@trillion01.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/napi.c b/io_uring/napi.c
index 6d5fdd397f2f4139304f02c3b0a2bdd69ace6853..1de1543d803440a6f3077e21a25141b3cb433374 100644 (file)
--- a/io_uring/napi.c
+++ b/io_uring/napi.c
@@ -137,15 +137,12 @@ static bool io_napi_busy_loop_should_end(void *data,
 }
 
 static bool __io_napi_do_busy_loop(struct io_ring_ctx *ctx,
+                                  bool (*loop_end)(void *, unsigned long),
                                   void *loop_end_arg)
 {
        struct io_napi_entry *e;
-       bool (*loop_end)(void *, unsigned long) = NULL;
        bool is_stale = false;
 
-       if (loop_end_arg)
-               loop_end = io_napi_busy_loop_should_end;
-
        list_for_each_entry_rcu(e, &ctx->napi_list, list) {
                napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg,
                                   ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET);
@@ -161,18 +158,22 @@ static void io_napi_blocking_busy_loop(struct io_ring_ctx *ctx,
                                       struct io_wait_queue *iowq)
 {
        unsigned long start_time = busy_loop_current_time();
+       bool (*loop_end)(void *, unsigned long) = NULL;
        void *loop_end_arg = NULL;
        bool is_stale = false;
 
        /* Singular lists use a different napi loop end check function and are
         * only executed once.
         */
-       if (list_is_singular(&ctx->napi_list))
+       if (list_is_singular(&ctx->napi_list)) {
+               loop_end = io_napi_busy_loop_should_end;
                loop_end_arg = iowq;
+       }
 
        scoped_guard(rcu) {
                do {
-                       is_stale = __io_napi_do_busy_loop(ctx, loop_end_arg);
+                       is_stale = __io_napi_do_busy_loop(ctx, loop_end,
+                                                         loop_end_arg);
                } while (!io_napi_busy_loop_should_end(iowq, start_time) &&
                         !loop_end_arg);
        }
@@ -308,7 +309,7 @@ int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx)
                return 0;
 
        scoped_guard(rcu) {
-               is_stale = __io_napi_do_busy_loop(ctx, NULL);
+               is_stale = __io_napi_do_busy_loop(ctx, NULL, NULL);
        }
 
        io_napi_remove_stale(ctx, is_stale);