On Wed, 2010-03-17 at 17:26 +0800, Zhang, Yanmin wrote: > On Tue, 2010-03-16 at 10:47 +0100, Ingo Molnar wrote: > > * Zhang, Yanmin <yanmin_zhang@xxxxxxxxxxxxxxx> wrote: > > > > > On Tue, 2010-03-16 at 15:48 +0800, Zhang, Yanmin wrote: > > > > On Tue, 2010-03-16 at 07:41 +0200, Avi Kivity wrote: > > > > > On 03/16/2010 07:27 AM, Zhang, Yanmin wrote: > > > > > > From: Zhang, Yanmin<yanmin_zhang@xxxxxxxxxxxxxxx> > > > > > > > > > > > > Based on the discussion in KVM community, I worked out the patch to support > > > > > > perf to collect guest os statistics from host side. This patch is implemented > > > > > > with Ingo, Peter and some other guys' kind help. Yang Sheng pointed out a > > > > > > critical bug and provided good suggestions with other guys. I really appreciate > > > > > > their kind help. > > > > > > > > > > > > The patch adds new subcommand kvm to perf. > > > > > > > > > > > > perf kvm top > > > > > > perf kvm record > > > > > > perf kvm report > > > > > > perf kvm diff > > > > > > > > > > > > The new perf could profile guest os kernel except guest os user space, but it > > > > > > could summarize guest os user space utilization per guest os. > > > > > > > > > > > > Below are some examples. > > > > > > 1) perf kvm top > > > > > > [root@lkp-ne01 norm]# perf kvm --host --guest --guestkallsyms=/home/ymzhang/guest/kallsyms > > > > > > --guestmodules=/home/ymzhang/guest/modules top > > > > > > > > > > > > > > > > > > > > > Thanks for your kind comments. > > > > > > > > > Excellent, support for guest kernel != host kernel is critical (I can't > > > > > remember the last time I ran same kernels). > > > > > > > > > > How would we support multiple guests with different kernels? > > > > With the patch, 'perf kvm report --sort pid" could show > > > > summary statistics for all guest os instances. Then, use > > > > parameter --pid of 'perf kvm record' to collect single problematic instance data. > > > Sorry. I found currently --pid isn't process but a thread (main thread). > > > > > > Ingo, > > > > > > Is it possible to support a new parameter or extend --inherit, so 'perf > > > record' and 'perf top' could collect data on all threads of a process when > > > the process is running? > > > > > > If not, I need add a new ugly parameter which is similar to --pid to filter > > > out process data in userspace. > > > > Yeah. For maximum utility i'd suggest to extend --pid to include this, and > > introduce --tid for the previous, limited-to-a-single-task functionality. > > > > Most users would expect --pid to work like a 'late attach' - i.e. to work like > > strace -f or like a gdb attach. > > Thanks Ingo, Avi. > > I worked out below patch against tip/master of March 15th. > > Subject: [PATCH] Change perf's parameter --pid to process-wide collection > From: Zhang, Yanmin <yanmin_zhang@xxxxxxxxxxxxxxx> > > Change parameter -p (--pid) to real process pid and add -t (--tid) meaning > thread id. Now, --pid means perf collects the statistics of all threads of > the process, while --tid means perf just collect the statistics of that thread. > > BTW, the patch fixes a bug of 'perf stat -p'. 'perf stat' always configures > attr->disabled=1 if it isn't a system-wide collection. If there is a '-p' > and no forks, 'perf stat -p' doesn't collect any data. In addition, the > while(!done) in run_perf_stat consumes 100% single cpu time which has bad impact > on running workload. I added a sleep(1) in the loop. > > Signed-off-by: Zhang Yanmin <yanmin_zhang@xxxxxxxxxxxxxxx> Ingo, Sorry, the patch has bugs. I need do a better job and will work out 2 separate patches against the 2 issues. Yanmin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
