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yaml
---
r: 234350
b: refs/heads/master
c: 04391de
h: refs/heads/master
v: v3
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Arnaldo Carvalho de Melo committed Jan 22, 2011
1 parent ae3fa03 commit 9a98aaa
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Showing 4 changed files with 70 additions and 54 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 98d77b78504a423fca911a26a17bee00ef2fdda2
refs/heads/master: 04391debc3e1195222a4dbb162ace6542dd89c1c
56 changes: 3 additions & 53 deletions trunk/tools/perf/builtin-top.c
Original file line number Diff line number Diff line change
Expand Up @@ -1100,67 +1100,17 @@ static void event__process_sample(const event_t *self,

static void perf_session__mmap_read_cpu(struct perf_session *self, int cpu)
{
struct perf_mmap *md = &evsel_list->mmap[cpu];
unsigned int head = perf_mmap__read_head(md);
unsigned int old = md->prev;
unsigned char *data = md->base + page_size;
struct sample_data sample;
int diff;

/*
* If we're further behind than half the buffer, there's a chance
* the writer will bite our tail and mess up the samples under us.
*
* If we somehow ended up ahead of the head, we got messed up.
*
* In either case, truncate and restart at head.
*/
diff = head - old;
if (diff > md->mask / 2 || diff < 0) {
fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");

/*
* head points to a known good entry, start there.
*/
old = head;
}

for (; old != head;) {
event_t *event = (event_t *)&data[old & md->mask];

event_t event_copy;

size_t size = event->header.size;

/*
* Event straddles the mmap boundary -- header should always
* be inside due to u64 alignment of output.
*/
if ((old & md->mask) + size != ((old + size) & md->mask)) {
unsigned int offset = old;
unsigned int len = min(sizeof(*event), size), cpy;
void *dst = &event_copy;

do {
cpy = min(md->mask + 1 - (offset & md->mask), len);
memcpy(dst, &data[offset & md->mask], cpy);
offset += cpy;
dst += cpy;
len -= cpy;
} while (len);

event = &event_copy;
}
event_t *event;

while ((event = perf_evlist__read_on_cpu(evsel_list, cpu)) != NULL) {
event__parse_sample(event, self, &sample);

if (event->header.type == PERF_RECORD_SAMPLE)
event__process_sample(event, &sample, self);
else
event__process(event, &sample, self);
old += size;
}

md->prev = old;
}

static void perf_session__mmap_read(struct perf_session *self)
Expand Down
62 changes: 62 additions & 0 deletions trunk/tools/perf/util/evlist.c
Original file line number Diff line number Diff line change
Expand Up @@ -95,3 +95,65 @@ struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
return sid->evsel;
return NULL;
}

event_t *perf_evlist__read_on_cpu(struct perf_evlist *evlist, int cpu)
{
/* XXX Move this to perf.c, making it generally available */
unsigned int page_size = sysconf(_SC_PAGE_SIZE);
struct perf_mmap *md = &evlist->mmap[cpu];
unsigned int head = perf_mmap__read_head(md);
unsigned int old = md->prev;
unsigned char *data = md->base + page_size;
event_t *event = NULL;
int diff;

/*
* If we're further behind than half the buffer, there's a chance
* the writer will bite our tail and mess up the samples under us.
*
* If we somehow ended up ahead of the head, we got messed up.
*
* In either case, truncate and restart at head.
*/
diff = head - old;
if (diff > md->mask / 2 || diff < 0) {
fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");

/*
* head points to a known good entry, start there.
*/
old = head;
}

if (old != head) {
size_t size;

event = (event_t *)&data[old & md->mask];
size = event->header.size;

/*
* Event straddles the mmap boundary -- header should always
* be inside due to u64 alignment of output.
*/
if ((old & md->mask) + size != ((old + size) & md->mask)) {
unsigned int offset = old;
unsigned int len = min(sizeof(*event), size), cpy;
void *dst = &evlist->event_copy;

do {
cpy = min(md->mask + 1 - (offset & md->mask), len);
memcpy(dst, &data[offset & md->mask], cpy);
offset += cpy;
dst += cpy;
len -= cpy;
} while (len);

event = &evlist->event_copy;
}

old += size;
}

md->prev = old;
return event;
}
4 changes: 4 additions & 0 deletions trunk/tools/perf/util/evlist.h
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@

#include <linux/list.h>
#include "../perf.h"
#include "event.h"

struct pollfd;

Expand All @@ -15,6 +16,7 @@ struct perf_evlist {
int nr_entries;
int nr_fds;
int mmap_len;
event_t event_copy;
struct perf_mmap *mmap;
struct pollfd *pollfd;
};
Expand All @@ -32,4 +34,6 @@ void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd);

struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id);

event_t *perf_evlist__read_on_cpu(struct perf_evlist *self, int cpu);

#endif /* __PERF_EVLIST_H */

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