Hi Shahina, 2012-11-29 (목), 13:45 +0530, Shahina Rabbani: > Hi Namhyung Kim , > > > First of all Thanks for your mail. > I have some more doubts. Please help me. > > > Q1: when we are working with more than one CPU, there will be a shared > L2 cache for all the CPUs and each CPU will have its own L1-cache > If i want to monitor a event and i am using L1-cahce and > L2-caches from CPU1 and the same time if CPU2 is also trying to > monotora particular event and using L2- > cache. Then how the perf tool handles this situation.
On a recent kernel and Intel cpus, it supports offcore and/or uncore events for that purpose AFAIK. Please check your cpu manuals. > > > Q2. Can you please list what are the architechtures it is supporting > at present. > > > Q3. Consider the case of Distributed systems, where the processors > are connected through the network and say i am trying to transmit data > over the TCP/IP stack. Is it > possible to monitor the data send at our end and data received > from the other end using the perf tool?? The perf tools work with pipe so that we might use nc/netcat for this. Only tested on a local machine: <on terminal 1> $ nc -l localhost 8282 | perf report -i - <on terminal 2> $ perf record -o - sleep 1 | nc localhost 8282 > > > Q4. when using perf record. Say i have got the data in perf.data file. > Say i am using this file to get some information and assume that > system crashes and the perf.data file is > in inconsistent state. when u reboot the system after the crash, > is it posssible to get the perf.data file safely.??? I doubt you can use the file safely. There's no guarantee when system crashed. Thanks, Namhyung > > > Q5. Say i am counting some samples depending on the clock. and assume > that i change the clock in between., Then the perf tool will be able > to understand the situation and count the samples depending on the old > and ne changed clocks or do we need to provide this information to > perf tool.?? how to handle this situation?? -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
