1. 19 Jul, 2017 38 commits
  2. 12 Jul, 2017 1 commit
    • Arnaldo Carvalho de Melo's avatar
      perf symbols: Accept zero as the kernel base address · 4b1303d0
      Arnaldo Carvalho de Melo authored
      Which is the case in S/390, where symbols were not being resolved
      because machine__get_kernel_start was only setting machine->kernel_start
      when the just successfully loaded kernel symtab had its map->start set
      to !0, when it was left at (1ULL << 63) assuming a partitioning of the
      address space for user/kernel, which is not the case in S/390 nor in
      Sparc.
      
      So just check if map__load() was successfull and set
      machine->kernel_start to zero, fixing kernel symbol resolution on S/390.
      
      Test performed by Thomas:
      
       ----
      
        I like this patch. I have done a new build and removed all my debug output to start
        from scratch. Without your patch I get this:
      
        # Samples: 4  of event 'cpu-clock'
        # Event count (approx.): 1000000
        #
        # Children      Self  Command  Shared Object     Symbol
        # ........  ........  .......  ................  ........................
            75.00%     0.00%  true     [unknown]         [k] 0x00000000004bedda
                    |
                    ---0x4bedda
                       |
                       |--50.00%--0x42693a
                       |          |
                       |           --25.00%--0x2a72e0
                       |                     0x2af0ca
                       |                     0x3d1003fe4c0
                       |
                        --25.00%--0x4272bc
                                  0x26fa84
      
        and with your patch (I just rebuilt the perf tool, nothing else and used the same
        perf.data file as input):
      
        # Samples: 4  of event 'cpu-clock'
        # Event count (approx.): 1000000
        #
        # Children      Self  Command  Shared Object               Symbol
        # ........  ........  .......  ..........................  ..................................
            75.00%     0.00%  true     [kernel.vmlinux]            [k] pgm_check_handler
                    |
                    ---pgm_check_handler
                       do_dat_exception
                       handle_mm_fault
                       __handle_mm_fault
                       filemap_map_pages
                       |
                       |--25.00%--rcu_read_lock_held
                       |          rcu_lockdep_current_cpu_online
                       |          0x3d1003ff4c0
                       |
                        --25.00%--lock_release
      
        Looks good to me....
       ----
      Reported-and-Tested-by: default avatarThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
      Link: http://lkml.kernel.org/n/tip-dk0n1uzmbe0tbthrpfqlx6bz@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      4b1303d0
  3. 11 Jul, 2017 1 commit