Laurent Desnogues wrote: > 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?
A "benchmark" I did was compiling lmbench, which became more than twice as fast. I didn't bother to do real measurements. > The boot of a Linux kernel > is quite heavy on various kinds of flushes and so is very > different from "standard" applications. At least the MIPS kernel is indeed different in that it uses non-trivial TLB mappings nearly excusively for modules and userland. IOW, the kernel-side MMU overhead at boot time is neglectable. My patch made no significant difference for that case. Thiemo _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel
