Re: [PATCH v2] seccomp: Improve performace by optimizing rmb()

From: Kees Cook
Date: Wed Feb 10 2021 - 15:46:27 EST


On Fri, 5 Feb 2021 11:34:09 +0800, wanghongzhe wrote:
> According to kees's suggest, we started with the patch that just replaces
> rmb() with smp_rmb() and did a performace test with UnixBench. The results
> showed the overhead about 2.53% in rmb() test compared to the smp_rmb()
> one, in a x86-64 kernel with CONFIG_SMP enabled running inside a qemu-kvm
> vm. The test is a "syscall" testcase in UnixBench, which executes 5
> syscalls in a loop during a certain timeout (100 second in our test) and
> counts the total number of executions of this 5-syscall sequence. We set a
> seccomp filter with all allow rule for all used syscalls in this test
> (which will go bitmap path) to make sure the rmb() will be executed. The
> details for the test:
>
> [...]

Applied to for-next/seccomp, thanks!

[1/1] seccomp: Improve performace by optimizing rmb()
https://git.kernel.org/kees/c/a381b70a1cf8

--
Kees Cook