• F
    tracing/kmemtrace: normalize the raw tracer event to the unified tracing API · 36994e58
    Frederic Weisbecker 提交于
    Impact: new tracer plugin
    
    This patch adapts kmemtrace raw events tracing to the unified tracing API.
    
    To enable and use this tracer, just do the following:
    
     echo kmemtrace > /debugfs/tracing/current_tracer
     cat /debugfs/tracing/trace
    
    You will have the following output:
    
     # tracer: kmemtrace
     #
     #
     # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
     # FREE   |      |     |       |              |   |            |        |
     # |
    
    type_id 1 call_site 18446744071565527833 ptr 18446612134395152256
    type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
    type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
    type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
    type_id 0 call_site 18446744071565636711 ptr 18446612134345164672 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
    type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
    type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
    type_id 0 call_site 18446744071565636711 ptr 18446612134345164912 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
    type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
    type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
    type_id 0 call_site 18446744071565636711 ptr 18446612134345165152 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
    type_id 0 call_site 18446744071566144042 ptr 18446612134346191680 bytes_req 1304 bytes_alloc 1312 gfp_flags 208 node -1
    type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
    type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
    type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
    
    That was to stay backward compatible with the format output produced in
    inux/tracepoint.h.
    
    This is the default ouput, but note that I tried something else.
    
    If you change an option:
    
    echo kmem_minimalistic > /debugfs/trace_options
    
    and then cat /debugfs/trace, you will have the following output:
    
     # tracer: kmemtrace
     #
     #
     # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
     # FREE   |      |     |       |              |   |            |        |
     # |
    
       -      C                            0xffff88007c088780          file_free_rcu
       +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
       -      C                            0xffff88007cad6000          putname
       +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
       +      K    240    240   000000d0   0xffff8800790dc780     -1   d_alloc
       -      C                            0xffff88007cad6000          putname
       +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
       +      K    240    240   000000d0   0xffff8800790dc870     -1   d_alloc
       -      C                            0xffff88007cad6000          putname
       +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
       +      K    240    240   000000d0   0xffff8800790dc960     -1   d_alloc
       +      K   1304   1312   000000d0   0xffff8800791d7340     -1   reiserfs_alloc_inode
       -      C                            0xffff88007cad6000          putname
       +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
       -      C                            0xffff88007cad6000          putname
       +      K    992   1000   000000d0   0xffff880079045b58     -1   alloc_inode
       +      K    768   1024   000080d0   0xffff88007c096400     -1   alloc_pipe_info
       +      K    240    240   000000d0   0xffff8800790dca50     -1   d_alloc
       +      K    272    320   000080d0   0xffff88007c088780     -1   get_empty_filp
       +      K    272    320   000080d0   0xffff88007c088000     -1   get_empty_filp
    
    Yeah I shall confess kmem_minimalistic should be: kmem_alternative.
    
    Whatever, I find it more readable but this a personal opinion of course.
    We can drop it if you want.
    
    On the ALLOC/FREE column, + means an allocation and - a free.
    
    On the type column, you have K = kmalloc, C = cache, P = page
    
    I would like the flags to be GFP_* strings but that would not be easy to not
    break the column with strings....
    
    About the node...it seems to always be -1. I don't know why but that shouldn't
    be difficult to find.
    
    I moved linux/tracepoint.h to trace/tracepoint.h as well. I think that would
    be more easy to find the tracer headers if they are all in their common
    directory.
    Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
    Signed-off-by: NIngo Molnar <mingo@elte.hu>
    36994e58
kmemtrace.c 8.0 KB