Hi Jinyu,

Pleae disable the KernelSkimWindow option (Meltdown fix) and try again?

ccmake . press t so you can see advanced options set the "KernelSkimWindow" option to "OFF"

Regards, Yanyan

On Sun, 2020-01-05 at 20:17 +0800, Dd Nirvana wrote:

Hi guys,

I have downloaded the lastest seL4 repo and built the seL4

kernel. And I reuse the code in sel4test/projects/sel4test/apps/sel4test- tests/src/tests/ipc.c. To test the fast, I made minor modifications: first, set caller and callee to the same priority; second, caller uses seL4_Call while callee uses seL4_ReplyRecv.

 However, the fastpath takes more than 2000 cycles (a round

trip).

 Build: use the lastest provided docker and ../init-build.sh -   
       DPLATFORM=x86_64 -DCMAKE_BUILD_TYPE=Release
 Both hardware and Qemu show similar results. (4.0GHz skylake

CPU)

 BTW. The manifest is the same as 

https://sel4.systems/About/Performance/home.pml (i.e., bf13e9f673484825a60f9950cf688ff33ac841ad).

Any advices about the issue?

Best, Jinyu Gu, Institute of Parallel and Distributed Systems (IPADS), School of Software, Shanghai Jiao Tong University _______________________________________________ Devel mailing list Devel@sel4.systems https://sel4.systems/lists/listinfo/devel