Re: [Qemu-devel] [PATCH] Huge TLB performance improvement

[Laurent Desnogues <laurent.desnogues@wanadoo.fr>]

Daniel Jacobowitz a écrit :
> 
> Straight qemu with my previously posted MIPS patches takes 6:13 to
> start and reboot a MIPS userspace (through init, so lots of fork/exec).
> 
> Thiemo's patch, which flushes the whole jump buffer, cuts it to 1:40.
> 
> A patch which finds the entries which need to be flushed more
> efficiently cuts it to 1:21.
> 
> A patch which flushes up to 1/32nd of the jump buffer indiscriminately
> cuts it to 1:11-1:13.

Warning:  I don't know anything about the Qemu MMU implementation
so this question is perhaps stupid :)

Did you try to benchmark some user space applications with the
various implementations you propose?  The boot of a Linux kernel
is quite heavy on various kinds of flushes and so is very
different from "standard" applications.


			Laurent