perf record: Move perf_mmap__write_tail to perf.h

Close to perf_mmap__read_head() and the perf_mmap struct definition.
This is useful for any recorder, and we will need it in 'perf test'.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2011-01-12 17:11:53 -02:00
parent 744bd8aa3c
commit 115d2d8963
2 changed files with 13 additions and 12 deletions

View File

@ -80,17 +80,6 @@ static const char *cpu_list;
static struct perf_mmap mmap_array[MAX_NR_CPUS];
static void mmap_write_tail(struct perf_mmap *md, unsigned long tail)
{
struct perf_event_mmap_page *pc = md->base;
/*
* ensure all reads are done before we write the tail out.
*/
/* mb(); */
pc->data_tail = tail;
}
static void advance_output(size_t size)
{
bytes_written += size;
@ -165,7 +154,7 @@ static void mmap_read(struct perf_mmap *md)
write_output(buf, size);
md->prev = old;
mmap_write_tail(md, old);
perf_mmap__write_tail(md, old);
}
static volatile int done = 0;

View File

@ -108,6 +108,18 @@ static inline unsigned int perf_mmap__read_head(struct perf_mmap *mm)
return head;
}
static inline void perf_mmap__write_tail(struct perf_mmap *md,
unsigned long tail)
{
struct perf_event_mmap_page *pc = md->base;
/*
* ensure all reads are done before we write the tail out.
*/
/* mb(); */
pc->data_tail = tail;
}
/*
* prctl(PR_TASK_PERF_EVENTS_DISABLE) will (cheaply) disable all
* counters in the current task.