liandao <[email protected]> 于2021年4月19日周一 下午4:07写道：
> i try jailhouse on NXP IMX8MM LPDDR4 EVK, and i test latency on root and > inmate. > most instructions are according i.MX_Linux_Users_Guide.pdf > (ver:L5.4.70_2.3.0) from NXP. > i build 3 type linux kernels: > 1)normal kernel > 2)kernel with PREEMPT-RT > 3)kernel with xenomai > we get the PREEMPT-RT patch and xenomai'Ipipe patch form an blog on i.MX > Forums/i.MX Processors Knowledge Base. > these linux config has turn off: CONFIG_CPU_FREQ/CONFIG_CPU_IDLE. > > a)when the root is an normal kernel or kernel with PREEMPT-RT, inmate is > gic-demo.bin, > do "stress-ng --cpu 4 --io 8 --vm 8 --vm-bytes 8M --fork 4 --udp 4 > --timeout 1h" in root linux > and within an hourse gic-demo can hit max 14us jitter. > > a)when the root is kernel with PREEMPT-RT, inmate is the kernel with > PREEMPT-RT, > run "cyclictest -l100000 -p99" in inmate linux,then max latency is about > 80us > > a)when the root is kernel with PREEMPT-RT, inmate is the kernel with > xenomai, > run "/usr/xenomai/bin/latency -t 0 -h -g ./202100419_01.log" in inmate > linux, > then max latency is about 50us-100us, > if root linux do nothing, the latency in inmate is better, > if do "stress-ng --cpu 4 --io 8 --vm 8 --vm-bytes 8M --fork 4 --udp 4 > --timeout 100s" in root linux, > the latency in inmate can hit 89us. > > my question is: while the latency in inmate linux is still so high?what > impact the inmate linux? how to get better latency in inmate? > run RTOS(not linux) in inmate? > Well. I think it is cache contention and DRAM bandwidth. Mostly it should be cache contention. Cache color should be a possible solution, but hard to support DMA. Regards, Peng. > -- > You received this message because you are subscribed to the Google Groups > "Jailhouse" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jailhouse-dev/7b5cf1d5-aef0-41bb-bedc-4350046e53c1n%40googlegroups.com > <https://groups.google.com/d/msgid/jailhouse-dev/7b5cf1d5-aef0-41bb-bedc-4350046e53c1n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/jailhouse-dev/CAEfxd-9smW4cjT3HfX%3DCuogd7GDNQjN2aixoMqP5ZNSkJaeAvQ%40mail.gmail.com.
