Re: [LSF/MM/BPF TOPIC] Measuring limits and enhancing buffered IO

Linus Torvalds
2024-02-24T18:24:39Z

On Sat, 24 Feb 2024 at 10:13, Matthew Wilcox <willy@infradead.org> wrote:
>
> > Ask yourself when you have last *really* sat there waiting for writes,
> > unless it's some dog-slow USB device that writes at 100kB/s?
>
> You picked a bad day to send this email ;-)
>
> $ sudo dd if=Downloads/debian-testing-amd64-netinst.iso of=/dev/sda

What? No. I literally picked the example you then did.

And you in fact were being clueless, and the kernel damn well should
tell you that you are being an ass, and should slow your writes down
so that you don't hurt others.

Which is what it did.

You should have damn well used oflag=direct, and if you didn't do
that, then the onus is all on YOU.

The kernel really isn't there to fix your stupid errors for you. You
do something stupid, the kernel will give you rope and happily say "do
you want more?"

Linus