1. 23 Dec, 2013 1 commit
    • Dongsheng Yang's avatar
      perf kvm: Fix kvm report without guestmount. · ad85ace0
      Dongsheng Yang authored
      Currently, if we use perf kvm --guestkallsyms --guestmodules report, we
      can not get the perf information from perf data file. All sample are
      shown as unknown.
      
      Reproducing steps:
      	# perf kvm --guestkallsyms /tmp/kallsyms --guestmodules /tmp/modules record -a sleep 1
      	[ perf record: Woken up 1 times to write data ]
      	[ perf record: Captured and wrote 0.624 MB perf.data.guest (~27260 samples) ]
      	# perf kvm --guestkallsyms /tmp/kallsyms --guestmodules /tmp/modules report |grep %
      	   100.00%  [guest/6471]  [unknown]         [g] 0xffffffff8164f330
      
      This bug was introduced by 207b5792 (perf kvm: Fix regression with guest machine creation).
      In original code, it uses perf_session__find_machine(), it means we deliver symbol to machine
      which has the same pid, if no machine found, deliver it to *default* guest. But if we use
      perf_session__findnew_machine() here, if no machine was found, new machine with pid will be built
      and added. Then the default guest which with pid == 0 will never get a symbol.
      
      And because the new machine initialized here has no kernel map created, the symbol delivered to
      it will be marked as "unknown".
      
      This patch here is to revert commit 207b5792 and fix the SEGFAULT bug in another way.
      
      Verification steps:
      	# ./perf kvm --guestkallsyms /home/kallsyms --guestmodules /home/modules record -a sleep 1
      	[ perf record: Woken up 1 times to write data ]
      	[ perf record: Captured and wrote 0.651 MB perf.data.guest (~28437 samples) ]
      	# ./perf kvm --guestkallsyms /home/kallsyms --guestmodules /home/modules report |grep %
      	    22.64%    :6471  [guest.kernel.kallsyms]  [g] update_rq_clock.part.70
      	    19.99%    :6471  [guest.kernel.kallsyms]  [g] d_free
      	    18.46%    :6471  [guest.kernel.kallsyms]  [g] bio_phys_segments
      	    16.25%    :6471  [guest.kernel.kallsyms]  [g] dequeue_task
      	    12.78%    :6471  [guest.kernel.kallsyms]  [g] __switch_to
      	     7.91%    :6471  [guest.kernel.kallsyms]  [g] scheduler_tick
      	     1.75%    :6471  [guest.kernel.kallsyms]  [g] native_apic_mem_write
      	     0.21%    :6471  [guest.kernel.kallsyms]  [g] apic_timer_interrupt
      Signed-off-by: default avatarDongsheng Yang <yangds.fnst@cn.fujitsu.com>
      Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
      Cc: stable@vger.kernel.org # 3.3+
      Cc: David Ahern <dsahern@gmail.com>
      Link: http://lkml.kernel.org/r/1387564907-3045-1-git-send-email-yangds.fnst@cn.fujitsu.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      ad85ace0
  2. 20 Dec, 2013 2 commits
  3. 19 Dec, 2013 28 commits
  4. 18 Dec, 2013 5 commits
  5. 17 Dec, 2013 4 commits