Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Mon, 15 Apr 2019 14:59:07 -0300 | Subject | Re: perf tools:Is there any tools to found out the max latency by irq or cpu idle |
| |
Em Mon, Apr 15, 2019 at 07:52:59AM -0500, Paul Clarke escreveu: > On 4/13/19 1:01 AM, Linhaifeng wrote: > > Sorry, the value 131081408 is just for example. Actually the result is like this: > > sqrt 2019-04-10 23:53:50: 43968 > > sqrt 2019-04-10 23:53:51: 44060 > > sqrt 2019-04-10 23:53:52: 49012 > > sqrt 2019-04-10 23:53:53: 38172 > > sqrt 2019-04-10 23:53:54: 131081408 > > sqrt 2019-04-10 23:53:55: 43600 > > sqrt 2019-04-10 23:53:56: 46704 > > sqrt 2019-04-10 23:53:57: 46880 > > sqrt 2019-04-10 23:53:58: 44332 > > …… > > sqrt 2019-04-10 02:17:15: 136345876 > > …… > > sqrt 2019-04-10 04:40:35: 136335644 > > …… > > Given the periodicity, I'm wondering if it could be System Management Interrupts (SMIs)? > > If so, some BIOSes have settings to mitigate, otherwise, there's not much that can be done, per my understanding.
[root@quaco perf]# perf list smi
List of pre-defined events (to be used in -e):
msr/smi/ [Kernel PMU event]
sunrpc:xprt_transmit [Tracepoint event] tcp:tcp_retransmit_skb [Tracepoint event] tcp:tcp_retransmit_synack [Tracepoint event]
sdt_qemu:qmp_block_job_dismiss [SDT event] sdt_qemu:qmp_job_dismiss [SDT event]
Metric Groups:
[root@quaco perf]#
Here, using it:
[root@quaco perf]# perf stat -I 1000 -e msr/smi/ # time counts unit events 1.000919819 0 msr/smi/ 2.001689950 0 msr/smi/ 3.002266988 0 msr/smi/ 4.003049439 16 msr/smi/ 5.003676064 0 msr/smi/ 6.004420613 16 msr/smi/ ^C 6.609405666 0 msr/smi/
[root@quaco perf]#
In this Lenovo T480s I generate SMIs by pressing the mute button :-)
- Arnaldo
| |