Re: [PATCH 0/2] Add BLK_FEAT_READ_SYNCHRONOUS and SWP_READ_SYNCHRONOUS_IO

[Huang, Ying]

Qun-Wei Lin <qun-wei.lin@xxxxxxxxxxxx> writes:

> This patchset introduces 2 new feature flags, BLK_FEAT_READ_SYNCHRONOUS and
> SWP_READ_SYNCHRONOUS_IO.
>
> These changes are motivated by the need to better accommodate certain swap
> devices that support synchronous read operations but asynchronous write
> operations.
>
> The existing BLK_FEAT_SYNCHRONOUS and SWP_SYNCHRONOUS_IO flags are not
> sufficient for these devices, as they enforce synchronous behavior for both
> read and write operations.

Which kind of device needs this?  Read fast, but write slow?

--
Best Regards,
Huang, Ying