diff options
author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-06-12 12:46:55 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-06-12 14:28:52 +0200 |
commit | 974802eaa1afdc87e00821df7020a2b3c6fee623 (patch) | |
tree | b5c38bece7f4948fe9d5cf9be02a0042e0fa39f6 /.gitignore | |
parent | bbd36e5e6aa6f1757c84cdb406b6eb81686d14af (diff) |
perf_counter: Add forward/backward attribute ABI compatibility
Provide for means of extending the perf_counter_attr in a 'natural' way.
We allow growing the structure by appending fields at the end by specifying
the full structure size inside it.
When a new kernel sees a smaller (old) structure, it will 0 pad the tail.
When an old kernel sees a larger (new) structure, it will verify the tail
consists of 0s, otherwise fail.
If we fail due to a size-mismatch, we return -E2BIG and write the kernel's
native attribe size back into the provided structure.
Furthermore, add some attribute verification, so that we'll fail counter
creation when unknown bits are present (PERF_SAMPLE, PERF_FORMAT, or in
the __reserved fields).
(This ABI detail is introduced while keeping the existing syscall ABI.)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to '.gitignore')
0 files changed, 0 insertions, 0 deletions