| Message ID | c9084c96-1771-6b7e-affb-2ac2e09e827d@kernel.dk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | io_uring: make sqpoll wakeup possible with getevents | expand |
Jens Axboe <axboe@kernel.dk> writes: > The way the logic is setup in io_uring_enter() means that you can't wake > up the SQ poller thread while at the same time waiting (or polling) for > completions afterwards. There's no reason for that to be the case. > > Reported-by: Lewis Baker <lbaker@fb.com> > Signed-off-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> > > -- > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index 4bc3ee4ea81f..3c8859d417eb 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -3356,15 +3356,12 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, > * Just return the requested submit count, and wake the thread if > * we were asked to. > */ > + ret = 0; > if (ctx->flags & IORING_SETUP_SQPOLL) { > if (flags & IORING_ENTER_SQ_WAKEUP) > wake_up(&ctx->sqo_wait); > submitted = to_submit; > - goto out_ctx; > - } > - > - ret = 0; > - if (to_submit) { > + } else if (to_submit) { > bool block_for_last = false; > > to_submit = min(to_submit, ctx->sq_entries); > @@ -3394,7 +3391,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, > } > } > > -out_ctx: > io_ring_drop_ctx_refs(ctx, 1); > out_fput: > fdput(f);
diff --git a/fs/io_uring.c b/fs/io_uring.c index 4bc3ee4ea81f..3c8859d417eb 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3356,15 +3356,12 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, * Just return the requested submit count, and wake the thread if * we were asked to. */ + ret = 0; if (ctx->flags & IORING_SETUP_SQPOLL) { if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sqo_wait); submitted = to_submit; - goto out_ctx; - } - - ret = 0; - if (to_submit) { + } else if (to_submit) { bool block_for_last = false; to_submit = min(to_submit, ctx->sq_entries); @@ -3394,7 +3391,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, } } -out_ctx: io_ring_drop_ctx_refs(ctx, 1); out_fput: fdput(f);
The way the logic is setup in io_uring_enter() means that you can't wake up the SQ poller thread while at the same time waiting (or polling) for completions afterwards. There's no reason for that to be the case. Reported-by: Lewis Baker <lbaker@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> --