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 <paulus@samba.org>
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 186efaf..c42455a 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -69,9 +69,10 @@
__s64 type;
__u64 irq_period;
- __u32 record_type;
+ __u64 record_type;
+ __u64 read_format;
- __u32 disabled : 1, /* off by default */
+ __u64 disabled : 1, /* off by default */
nmi : 1, /* NMI sampling */
raw : 1, /* raw event type */
inherit : 1, /* children inherit it */
@@ -80,10 +81,15 @@
exclude_user : 1, /* don't count user */
exclude_kernel : 1, /* ditto kernel */
exclude_hv : 1, /* ditto hypervisor */
+ exclude_idle : 1, /* don't count when idle */
- __reserved_1 : 23;
+ __reserved_1 : 55;
+
+ __u32 extra_config_len;
+ __u32 __reserved_4;
__u64 __reserved_2;
+ __u64 __reserved_3;
};
/*
