| Message ID | 20230419162552.576489-3-axboe@kernel.dk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Enable NO_OFFLOAD support | expand |
On 4/19/23 17:25, Jens Axboe wrote: > After bumping the flags to 64-bits, we now have two holes in io_kiocb. > The best candidate for moving is poll_refs, as not to split the task_work > related items. > > Signed-off-by: Jens Axboe <axboe@kernel.dk> > --- > include/linux/io_uring_types.h | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h > index 84f436cc6509..4dd54d2173e1 100644 > --- a/include/linux/io_uring_types.h > +++ b/include/linux/io_uring_types.h > @@ -535,6 +535,9 @@ struct io_kiocb { > * and after selection it points to the buffer ID itself. > */ > u16 buf_index; > + > + atomic_t poll_refs; poll wake is often done by a random CPU, would be great to limit cache sharing, i.e. the 2nd cache line is never touched by io_poll_wake() and it'd only need the poll entry and the 3rd line with io_task_work(). There is one place that doesn't care about it, i.e. clearing REQ_F_[SINGLE,DOUBLE]_POLL in poll wake, but it's a place to improve. > + > u64 flags; > > struct io_cqe cqe; > @@ -565,9 +568,8 @@ struct io_kiocb { > __poll_t apoll_events; > }; > atomic_t refs; > - atomic_t poll_refs; > - struct io_task_work io_task_work; > unsigned nr_tw; > + struct io_task_work io_task_work; > /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ > union { > struct hlist_node hash_node;
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 84f436cc6509..4dd54d2173e1 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -535,6 +535,9 @@ struct io_kiocb { * and after selection it points to the buffer ID itself. */ u16 buf_index; + + atomic_t poll_refs; + u64 flags; struct io_cqe cqe; @@ -565,9 +568,8 @@ struct io_kiocb { __poll_t apoll_events; }; atomic_t refs; - atomic_t poll_refs; - struct io_task_work io_task_work; unsigned nr_tw; + struct io_task_work io_task_work; /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ union { struct hlist_node hash_node;
After bumping the flags to 64-bits, we now have two holes in io_kiocb. The best candidate for moving is poll_refs, as not to split the task_work related items. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- include/linux/io_uring_types.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)