Re: [PATCH v6 10/11] blksnap: Kconfig and Makefile

Christoph Hellwig
2023-12-07T07:47:33Z

> +config BLKSNAP_DIFF_BLKDEV
> + bool "Use an optimized algorithm to store difference on a block device"
> + depends on BLKSNAP
> + default y
> + help
> + The difference storage for a snapshot can be a regular file or a
> + block device. We can work with a block device through the interface
> + of a regular file. However, direct management of I/O units should
> + allow for higher performance.

Is there much of a point in making this option?

Btw, Linus hates defaul y, so we should not have one in there.

> +config BLKSNAP_CHUNK_DIFF_BIO_SYNC
> + bool "Use a synchronous I/O unit processing algorithm for the snapshot image"
> + depends on BLKSNAP
> + default n

n the default default, so no need to add it. But unless there is a
really good reason to have two different bio submission mechanisms
upstream I'd strongly suggest dropping one of them and this option.