Re: [PATCH] sysctl: Add a feature to drop caches selectively

Artem Bityutskiy
2014-06-27T09:08:31Z

On Fri, 2014-06-27 at 10:41 +0200, Matthias Schniedermeyer wrote:
> On 26.06.2014 13:57, Luká? Czerner wrote:
>
> > > So if the authors want to sell this new interface (in whatever form) to
> > > the kernel community, they should start with providing a solid use-case,
> > > with some more details, explore alternatives and show how the
> > > alternatives do not work for them.
> >
> > Yes please, let's see some solid use-case for this.
>
> Personally i would want it to verify files after copying them:
> Especially while moving files:
> - Copy a file
> - <drop cache>
> - Verify that it really is correct on stable storage
> - Remove original file

To make 100% sure you'd not only need to drop VFS-level caches but also
file-system-level caches. Indeed, file-systems have their own rather
buffers for different indexing data-structures, etc. The unmount/mount
sequence takes care of that.

--
Best Regards,
Artem Bityutskiy