On 1/17/20 3:41 PM, Pavel Begunkov wrote:
> *lost the cover-letter, but here we go*
>
> The main idea is to optimise code like the following by directly
> copying sqe flags:
>
> if (sqe_flags & IOSQE_IO_HARDLINK)
> req->flags |= REQ_F_HARDLINK;
>
> The first patch is a minor cleanup, and the second one do the
> trick. No functional changes.
>
> The other thing to consider is whether to use such flags as
> REQ_F_LINK = IOSQE_IO_LINK, or directly use IOSQE_IO_LINK instead.
I think we should keep the names separate. I think it looks fine, though
I do wish that we could just have both in an enum and not have to do
weird naming. We sometimes do:
enum {
__REQ_F_FOO
};
#define REQ_F_FOO (1U << __REQ_F_FOO)
and with that we could have things Just Work in terms of numbering, if
we keep the overlapped values at the start. Would need IOSQE_* to also
use an enum, ala:
enum {
__IOSQE_FIXED_FILE,
__IOSQE_IO_DRAIN,
...
};
and then do
#define IOSQE_FIXED_FILE (1U << __IOSQE_FIXED_FILE)
and have the __REQ enum start with
enum {
__REQ_F_FIXED_FILE = __IOSQE_FIXED_FILE,
__REQ_F_IO_DRAIN = __IOSQE_IO_DRAIN,
...
__REQ_F_LINK_NEXT,
__REQ_F_FAIL_LINK,
...
};
--
Jens Axboe
