On Mon, 19 Aug 2013 18:46:20 +0900 Yoshihiro YUNOMAE <yoshihiro.yunomae...@hitachi.com> wrote:
> d) merge feature of trace data of multiple guests and a host in chronological > order > Current trace-cmd cannot merge trace data of multiple guests and a host in > chronological order. If an user wants to analyze an I/O delay problem of a > guest, the user will want to check trace data of all guests and the host in a > file. However, trace-cmd does not support a merge feature yet, the user must > make a merging script. So, trace-cmd had better support a merge feature for > multiple files for virtualization. > This is incorrect. trace-cmd already has a merge feature for multiple machines. If you have two boxes that are in sync by ntp, you can do the following: On box1: trace-cmd record --date -o trace-box1.dat -e all ping box2 On box2: trace-cmd record --date -o trace-box2.dat -e all ping box1 And then copy over trace-box2.dat to box1 and run trace-cmd report -i trace-box1.dat -i trace-box2.dat And you will see a merge. I just did this on two of my boxes called ixf and bxtest and here's a partial output: trace-bxtest.dat: trace-cmd-1348 [003] 1377013771.682807: sys_enter: NR 2 (22e2b00, 241, 1a4, 1a, 4361ac, 3) trace-bxtest.dat: trace-cmd-1348 [003] 1377013771.682808: sys_enter_open: filename: 0x022e2b00, flags: 0x00000241, mode: 0x000001a4 trace-ixf.dat: <idle>-0 [002] 1377013771.682808: hrtimer_cancel: hrtimer=0xffff880002110820 trace-ixf.dat: <idle>-0 [002] 1377013771.682808: hrtimer_expire_entry: hrtimer=0xffff880002110820 now=673528250850 function=tick_sched_timer/0x0 trace-bxtest.dat: trace-cmd-1348 [003] 1377013771.682809: kmem_cache_alloc: (getname_flags+0x37) call_site=ffffffff8117b797 ptr=0xffff8800d38c0000 bytes_req=4096 bytes_alloc=4096 gfp_flags=GFP_KERNELGFP_NOTRACK The --date option is used because the two machines are not in sync with the trace time stamp. What the date option does, is to sync the timestamp up with the gettimeofday and the output reports that. This allows the two boxes to report information that is relatively close to how the two interacted. If the guest and the host have the same clock, then the --date option is not needed and the two should be able to be merged normally. Also, I haven't released it yet (will soon), but trace-cmd handles multiple buffers too. That is, with the multiple buffers that ftrace has, it will create and read from them as well as report them. I'll finish my testing on all the latest features of trace-cmd I have and push it out later today. I'll also take a look at the rest of your patches. Thanks, -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/