From: Jens Axboe Date: Mon, 11 Mar 2024 19:30:43 +0000 (-0600) Subject: io_uring: don't save/restore iowait state X-Git-Tag: v6.8.2~77 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e0b39f2e6acc28bea6b0d8cc93ad32e1bb5f0378;p=thirdparty%2Fkernel%2Fstable.git io_uring: don't save/restore iowait state [ Upstream commit 6f0974eccbf78baead1735722c4f1ee3eb9422cd ] This kind of state is per-syscall, and since we're doing the waiting off entering the io_uring_enter(2) syscall, there's no way that iowait can already be set for this case. Simplify it by setting it if we need to, and always clearing it to 0 when done. Fixes: 7b72d661f1f2 ("io_uring: gate iowait schedule on having pending requests") Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 39dfb83dc9fc4..030cc930d1c6a 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2527,7 +2527,7 @@ static bool current_pending_io(void) static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) { - int io_wait, ret; + int ret; if (unlikely(READ_ONCE(ctx->check_cq))) return 1; @@ -2545,7 +2545,6 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, * can take into account that the task is waiting for IO - turns out * to be important for low QD IO. */ - io_wait = current->in_iowait; if (current_pending_io()) current->in_iowait = 1; ret = 0; @@ -2553,7 +2552,7 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, schedule(); else if (!schedule_hrtimeout(&iowq->timeout, HRTIMER_MODE_ABS)) ret = -ETIME; - current->in_iowait = io_wait; + current->in_iowait = 0; return ret; }