Re: [MirageOS-devel] Mirage questions from writing a REST service

[David Scott <scott.dj@xxxxxxxxx>]

Hi,

Very enjoyable post!

On 29 Jul 2014 13:04, "Thomas Leonard" <talex5@xxxxxxxxx> wrote:
>
> On 7 July 2014 10:08, Thomas Leonard <talex5@xxxxxxxxx> wrote:
> > I'm writing a test Mirage service for queuing files. It's not using
> > ThomasG's merge-queues - I'm just trying the low-level FS stuff first.
> >
>
> I did some more tests and wrote the results up here:
>
> Â http://roscidus.com/blog/blog/2014/07/28/my-first-unikernel/
>
> In summary:
>
> 1. Adding a block cache helped a bit, but it was still too slow.

I think a cache would be helpful for many applications. It's always a bit painful to disable caching on linux-- O_DIRECT doesn't always work, and then you have to align all your buffers. I like the uncached-by-default behaviour of Mirage, but we should make it easier to turn caching back on.

> 2. Dropping FAT and writing directly to the SD card helped a lot.

I think we should concentrate on a block backend for Irmin and label FAT as not part of the Mirage "core". FAT will always be useful for things like making a bootable disk image containing a kernel but it'll never be a drop-in replacement for a modern Linux filesystem :-)

> 3. It's now fast enough for my use, but still slower than I was expecting.

It's very easy to make a small change which hammers performance. I think
I'll concentrate on writing performance tests which can run from a CI when I'm back.

Thanks,
Dave
>
>
> --
> Dr Thomas Leonard    Âhttp://0install.net/
> GPG: 9242 9807 C985 3C07 44A6 Â8B9A AE07 8280 59A5 3CC1
> GPG: DA98 25AE CAD0 8975 7CDA ÂBD8E 0713 3F96 CA74 D8BA
>
> _______________________________________________
> MirageOS-devel mailing list
> MirageOS-devel@xxxxxxxxxxxxxxxxxxxx
> http://lists.xenproject.org/cgi-bin/mailman/listinfo/mirageos-devel

_______________________________________________
MirageOS-devel mailing list
MirageOS-devel@xxxxxxxxxxxxxxxxxxxx
http://lists.xenproject.org/cgi-bin/mailman/listinfo/mirageos-devel