On 9/10/24 09:02, Christoph Hellwig wrote:
On Fri, Sep 06, 2024 at 11:57:25PM +0100, Pavel Begunkov wrote:
Add a command that writes the zero page to the drive. Apart from passing
the zero page instead of actual data it uses the normal write path and
doesn't do any further acceleration, nor it requires any special
hardware support. The indended use is to have a fallback when
BLOCK_URING_CMD_WRITE_ZEROES is not supported.
That's just a horrible API. The user should not have to care if the
kernel is using different kinds of implementations.
It's rather not a good api when instead of issuing a presumably low
overhead fast command the user expects sending a good bunch of actual
writes with different performance characteristics. In my experience,
such fallbacks cause more pain when a more explicit approach is
possible. And let me note that it's already exposed via fallocate, even
though in a bit different way.
--
Pavel Begunkov
