Re: [PATCH 11/11] scsi: ufs: Implement polling support

Bart Van Assche
2021-11-19T19:39:35Z

On 11/9/21 17:36, Douglas Gilbert wrote:
> On 2021-11-09 7:44 p.m., Bart Van Assche wrote:
>> The time spent in io_schedule() is significant when submitting direct
>> I/O to a UFS device. Hence this patch that implements polling support.
>> User space software can enable polling by passing the RWF_HIPRI flag to
>> the preadv2() system call or the IORING_SETUP_IOPOLL flag to the
>> io_uring interface.
>
> There have been some changes recently (i.e. in linux-stable now),
> "HIPRI" seems to be on the out, replaced by "POLLED". [I'm using
> poll_lld in my sg rewrite to refer to this type of polling, as "poll"
> is an overloaded term in the kernel].
>
> REQ_HIPRI has become REQ_POLLED and blk_poll() is now bio_poll().
> That said RWF_HIPRI is still in fs.h and there is no RWF_POLLED (yet).

Hi Doug,

My reference to RWF_HIPRI in the patch description refers to the flag
defined in the uapi headers. As far as I know that flag is still there:

$ PAGER= git grep define.RWF_HIPRI include/uapi
include/uapi/linux/fs.h:#define RWF_HIPRI ((__force __kernel_rwf_t)0x00000001)

Thanks,

Bart.