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perf_counter: use misc field to widen type
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Push the PERF_EVENT_COUNTER_OVERFLOW bit into the misc field so that
we can have the full 32bit for PERF_RECORD_ bits.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090408130408.891867663@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Peter Zijlstra authored and Ingo Molnar committed Apr 8, 2009
1 parent 6fab019 commit 6b6e548
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Showing 2 changed files with 18 additions and 25 deletions.
28 changes: 10 additions & 18 deletions include/linux/perf_counter.h
Original file line number Diff line number Diff line change
Expand Up @@ -201,8 +201,9 @@ struct perf_counter_mmap_page {
__u32 data_head; /* head in the data section */
};

#define PERF_EVENT_MISC_KERNEL (1 << 0)
#define PERF_EVENT_MISC_USER (1 << 1)
#define PERF_EVENT_MISC_KERNEL (1 << 0)
#define PERF_EVENT_MISC_USER (1 << 1)
#define PERF_EVENT_MISC_OVERFLOW (1 << 2)

struct perf_event_header {
__u32 type;
Expand Down Expand Up @@ -230,36 +231,27 @@ enum perf_event_type {
PERF_EVENT_MUNMAP = 2,

/*
* Half the event type space is reserved for the counter overflow
* bitfields, as found in hw_event.record_type.
*
* These events will have types of the form:
* PERF_EVENT_COUNTER_OVERFLOW { | __PERF_EVENT_* } *
* When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field
* will be PERF_RECORD_*
*
* struct {
* struct perf_event_header header;
*
* { u64 ip; } && __PERF_EVENT_IP
* { u32 pid, tid; } && __PERF_EVENT_TID
* { u64 ip; } && PERF_RECORD_IP
* { u32 pid, tid; } && PERF_RECORD_TID
*
* { u64 nr;
* { u64 event, val; } cnt[nr]; } && __PERF_EVENT_GROUP
* { u64 event, val; } cnt[nr]; } && PERF_RECORD_GROUP
*
* { u16 nr,
* hv,
* kernel,
* user;
* u64 ips[nr]; } && __PERF_EVENT_CALLCHAIN
* u64 ips[nr]; } && PERF_RECORD_CALLCHAIN
*
* { u64 time; } && __PERF_EVENT_TIME
* { u64 time; } && PERF_RECORD_TIME
* };
*/
PERF_EVENT_COUNTER_OVERFLOW = 1UL << 31,
__PERF_EVENT_IP = PERF_RECORD_IP,
__PERF_EVENT_TID = PERF_RECORD_TID,
__PERF_EVENT_GROUP = PERF_RECORD_GROUP,
__PERF_EVENT_CALLCHAIN = PERF_RECORD_CALLCHAIN,
__PERF_EVENT_TIME = PERF_RECORD_TIME,
};

#ifdef __KERNEL__
Expand Down
15 changes: 8 additions & 7 deletions kernel/perf_counter.c
Original file line number Diff line number Diff line change
Expand Up @@ -1828,15 +1828,16 @@ static void perf_counter_output(struct perf_counter *counter,
int callchain_size = 0;
u64 time;

header.type = PERF_EVENT_COUNTER_OVERFLOW;
header.type = 0;
header.size = sizeof(header);

header.misc = user_mode(regs) ?
header.misc = PERF_EVENT_MISC_OVERFLOW;
header.misc |= user_mode(regs) ?
PERF_EVENT_MISC_USER : PERF_EVENT_MISC_KERNEL;

if (record_type & PERF_RECORD_IP) {
ip = instruction_pointer(regs);
header.type |= __PERF_EVENT_IP;
header.type |= PERF_RECORD_IP;
header.size += sizeof(ip);
}

Expand All @@ -1845,12 +1846,12 @@ static void perf_counter_output(struct perf_counter *counter,
tid_entry.pid = current->group_leader->pid;
tid_entry.tid = current->pid;

header.type |= __PERF_EVENT_TID;
header.type |= PERF_RECORD_TID;
header.size += sizeof(tid_entry);
}

if (record_type & PERF_RECORD_GROUP) {
header.type |= __PERF_EVENT_GROUP;
header.type |= PERF_RECORD_GROUP;
header.size += sizeof(u64) +
counter->nr_siblings * sizeof(group_entry);
}
Expand All @@ -1861,7 +1862,7 @@ static void perf_counter_output(struct perf_counter *counter,
if (callchain) {
callchain_size = (1 + callchain->nr) * sizeof(u64);

header.type |= __PERF_EVENT_CALLCHAIN;
header.type |= PERF_RECORD_CALLCHAIN;
header.size += callchain_size;
}
}
Expand All @@ -1872,7 +1873,7 @@ static void perf_counter_output(struct perf_counter *counter,
*/
time = sched_clock();

header.type |= __PERF_EVENT_TIME;
header.type |= PERF_RECORD_TIME;
header.size += sizeof(u64);
}

Expand Down

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