Loading the ramdisk takes an insanely long time

[NikoPit]

Currently i have a 64MB ramdisk, and it takes like 30 seconds to load.
this is probably not normal
please lmk if you need the build.rs or source code

[NikoPit]

loading the kernel also takes a long time but its not as long as the ramdisk

[Freax13]

You mentioned that you don't use hardware virtualization. Are you sure that the bottleneck isn't caused by QEMU TCG's inherently lower performance? I'm guessing that the device drivers in the BIOS aren't all that optimized either, so loading any big file in a bootloader is going to be slow unless one replaces the disk driver.

[NikoPit]

does enabling hardware virtualization means enabling kvm?

[Freax13]

That'd be one way of enabling hardware virtualization, yes.

[NikoPit]

no, its still extremely laggy. i added --enable-kvm to it

[Freax13]

Yeah, the BIOS bootloader is significantly slower than the UEFI one.

I think the main root cause seems to be that we're doing a lot of small disk accesses. I tried merging multiple FAT clusters to do larger reads for several clusters at once and that got the runtime of the large_ramdisk test down from 35s to 10s.

[NikoPit]

fixed on #550