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Diffstat (limited to 'Documentation/ABI/testing')
| -rw-r--r-- | Documentation/ABI/testing/debugfs-kmemtrace | 71 |
1 files changed, 0 insertions, 71 deletions
diff --git a/Documentation/ABI/testing/debugfs-kmemtrace b/Documentation/ABI/testing/debugfs-kmemtrace deleted file mode 100644 index 5e6a92a02d85..000000000000 --- a/Documentation/ABI/testing/debugfs-kmemtrace +++ /dev/null @@ -1,71 +0,0 @@ -What: /sys/kernel/debug/kmemtrace/ -Date: July 2008 -Contact: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> -Description: - -In kmemtrace-enabled kernels, the following files are created: - -/sys/kernel/debug/kmemtrace/ - cpu<n> (0400) Per-CPU tracing data, see below. (binary) - total_overruns (0400) Total number of bytes which were dropped from - cpu<n> files because of full buffer condition, - non-binary. (text) - abi_version (0400) Kernel's kmemtrace ABI version. (text) - -Each per-CPU file should be read according to the relay interface. That is, -the reader should set affinity to that specific CPU and, as currently done by -the userspace application (though there are other methods), use poll() with -an infinite timeout before every read(). Otherwise, erroneous data may be -read. The binary data has the following _core_ format: - - Event ID (1 byte) Unsigned integer, one of: - 0 - represents an allocation (KMEMTRACE_EVENT_ALLOC) - 1 - represents a freeing of previously allocated memory - (KMEMTRACE_EVENT_FREE) - Type ID (1 byte) Unsigned integer, one of: - 0 - this is a kmalloc() / kfree() - 1 - this is a kmem_cache_alloc() / kmem_cache_free() - 2 - this is a __get_free_pages() et al. - Event size (2 bytes) Unsigned integer representing the - size of this event. Used to extend - kmemtrace. Discard the bytes you - don't know about. - Sequence number (4 bytes) Signed integer used to reorder data - logged on SMP machines. Wraparound - must be taken into account, although - it is unlikely. - Caller address (8 bytes) Return address to the caller. - Pointer to mem (8 bytes) Pointer to target memory area. Can be - NULL, but not all such calls might be - recorded. - -In case of KMEMTRACE_EVENT_ALLOC events, the next fields follow: - - Requested bytes (8 bytes) Total number of requested bytes, - unsigned, must not be zero. - Allocated bytes (8 bytes) Total number of actually allocated - bytes, unsigned, must not be lower - than requested bytes. - Requested flags (4 bytes) GFP flags supplied by the caller. - Target CPU (4 bytes) Signed integer, valid for event id 1. - If equal to -1, target CPU is the same - as origin CPU, but the reverse might - not be true. - -The data is made available in the same endianness the machine has. - -Other event ids and type ids may be defined and added. Other fields may be -added by increasing event size, but see below for details. -Every modification to the ABI, including new id definitions, are followed -by bumping the ABI version by one. - -Adding new data to the packet (features) is done at the end of the mandatory -data: - Feature size (2 byte) - Feature ID (1 byte) - Feature data (Feature size - 3 bytes) - - -Users: - kmemtrace-user - git://repo.or.cz/kmemtrace-user.git - |
