From: Paul Mackerras Date: Wed, 4 Mar 2009 09:36:51 +0000 (+1100) Subject: perfcounters: provide expansion room in the ABI X-Git-Tag: v2.6.31-rc1~383^2~493^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2743a5b0fa6f309da904f2190a9cc25deee34dbd;p=pandora-kernel.git perfcounters: provide expansion room in the ABI Impact: ABI change This expands several fields in the perf_counter_hw_event struct and adds a "flags" argument to the perf_counter_open system call, in order that features can be added in future without ABI changes. In particular the record_type field is expanded to 64 bits, and the space for flag bits has been expanded from 32 to 64 bits. This also adds some new fields: * read_format (64 bits) is intended to provide a way to specify what userspace wants to get back when it does a read() on a simple (non-interrupting) counter; * exclude_idle (1 bit) provides a way for userspace to ask that events that occur when the cpu is idle be excluded; * extra_config_len will provide a way for userspace to supply an arbitrary amount of extra machine-specific PMU configuration data immediately following the perf_counter_hw_event struct, to allow sophisticated users to program things such as instruction matching CAMs and address range registers; * __reserved_3 and __reserved_4 provide space for future expansion. Signed-off-by: Paul Mackerras --- Reading git-diff-tree failed