[tip:perf/core] perf cs-etm: Add support for multiple traceID queues

From: tip-bot for Mathieu Poirier
Date: Mon Jun 17 2019 - 15:34:36 EST


Commit-ID: c152d4d49a358224d73cb7ce7cc6090676b04931
Gitweb: https://git.kernel.org/tip/c152d4d49a358224d73cb7ce7cc6090676b04931
Author: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
AuthorDate: Fri, 24 May 2019 11:35:05 -0600
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 10 Jun 2019 15:50:02 -0300

perf cs-etm: Add support for multiple traceID queues

When operating in CPU-wide trace mode with a source/sink topology of N:1
packets with multiple traceID will end up in the same cs_etm_queue. In
order to properly decode packets they need to be split in different
queues, i.e one queue per traceID.

As such add support for multiple traceID per cs_etm_queue by adding a
new cs_etm_traceid_queue every time a new traceID is discovered in the
trace stream.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Tested-by: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx>
Cc: coresight@xxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190524173508.29044-15-mathieu.poirier@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Makefile.config | 3 ++
tools/perf/util/cs-etm.c | 131 ++++++++++++++++++++++++++++++++++++---------
2 files changed, 110 insertions(+), 24 deletions(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 85fbcd265351..51dd00f65709 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -413,6 +413,9 @@ ifdef CORESIGHT
$(call feature_check,libopencsd)
ifeq ($(feature-libopencsd), 1)
CFLAGS += -DHAVE_CSTRACE_SUPPORT $(LIBOPENCSD_CFLAGS)
+ ifeq ($(feature-reallocarray), 0)
+ CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
+ endif
LDFLAGS += $(LIBOPENCSD_LDFLAGS)
EXTLIBS += $(OPENCSDLIBS)
$(call detected,CONFIG_LIBOPENCSD)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 2483293266d8..afc2491f9f2a 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -29,6 +29,7 @@
#include "thread.h"
#include "thread_map.h"
#include "thread-stack.h"
+#include <tools/libc_compat.h>
#include "util.h"

#define MAX_TIMESTAMP (~0ULL)
@@ -82,7 +83,9 @@ struct cs_etm_queue {
u64 offset;
const unsigned char *buf;
size_t buf_len, buf_used;
- struct cs_etm_traceid_queue *traceid_queues;
+ /* Conversion between traceID and index in traceid_queues array */
+ struct intlist *traceid_queues_list;
+ struct cs_etm_traceid_queue **traceid_queues;
};

static int cs_etm__update_queues(struct cs_etm_auxtrace *etm);
@@ -208,31 +211,71 @@ out:
static struct cs_etm_traceid_queue
*cs_etm__etmq_get_traceid_queue(struct cs_etm_queue *etmq, u8 trace_chan_id)
{
- struct cs_etm_traceid_queue *tidq;
+ int idx;
+ struct int_node *inode;
+ struct intlist *traceid_queues_list;
+ struct cs_etm_traceid_queue *tidq, **traceid_queues;
struct cs_etm_auxtrace *etm = etmq->etm;

- if (!etm->timeless_decoding)
- return NULL;
+ if (etm->timeless_decoding)
+ trace_chan_id = CS_ETM_PER_THREAD_TRACEID;

- tidq = etmq->traceid_queues;
+ traceid_queues_list = etmq->traceid_queues_list;

- if (tidq)
- return tidq;
+ /*
+ * Check if the traceid_queue exist for this traceID by looking
+ * in the queue list.
+ */
+ inode = intlist__find(traceid_queues_list, trace_chan_id);
+ if (inode) {
+ idx = (int)(intptr_t)inode->priv;
+ return etmq->traceid_queues[idx];
+ }

+ /* We couldn't find a traceid_queue for this traceID, allocate one */
tidq = malloc(sizeof(*tidq));
if (!tidq)
return NULL;

memset(tidq, 0, sizeof(*tidq));

+ /* Get a valid index for the new traceid_queue */
+ idx = intlist__nr_entries(traceid_queues_list);
+ /* Memory for the inode is free'ed in cs_etm_free_traceid_queues () */
+ inode = intlist__findnew(traceid_queues_list, trace_chan_id);
+ if (!inode)
+ goto out_free;
+
+ /* Associate this traceID with this index */
+ inode->priv = (void *)(intptr_t)idx;
+
if (cs_etm__init_traceid_queue(etmq, tidq, trace_chan_id))
goto out_free;

- etmq->traceid_queues = tidq;
+ /* Grow the traceid_queues array by one unit */
+ traceid_queues = etmq->traceid_queues;
+ traceid_queues = reallocarray(traceid_queues,
+ idx + 1,
+ sizeof(*traceid_queues));
+
+ /*
+ * On failure reallocarray() returns NULL and the original block of
+ * memory is left untouched.
+ */
+ if (!traceid_queues)
+ goto out_free;
+
+ traceid_queues[idx] = tidq;
+ etmq->traceid_queues = traceid_queues;

- return etmq->traceid_queues;
+ return etmq->traceid_queues[idx];

out_free:
+ /*
+ * Function intlist__remove() removes the inode from the list
+ * and delete the memory associated to it.
+ */
+ intlist__remove(traceid_queues_list, inode);
free(tidq);

return NULL;
@@ -412,6 +455,44 @@ static int cs_etm__flush_events(struct perf_session *session,
return cs_etm__process_timeless_queues(etm, -1);
}

+static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq)
+{
+ int idx;
+ uintptr_t priv;
+ struct int_node *inode, *tmp;
+ struct cs_etm_traceid_queue *tidq;
+ struct intlist *traceid_queues_list = etmq->traceid_queues_list;
+
+ intlist__for_each_entry_safe(inode, tmp, traceid_queues_list) {
+ priv = (uintptr_t)inode->priv;
+ idx = priv;
+
+ /* Free this traceid_queue from the array */
+ tidq = etmq->traceid_queues[idx];
+ thread__zput(tidq->thread);
+ zfree(&tidq->event_buf);
+ zfree(&tidq->last_branch);
+ zfree(&tidq->last_branch_rb);
+ zfree(&tidq->prev_packet);
+ zfree(&tidq->packet);
+ zfree(&tidq);
+
+ /*
+ * Function intlist__remove() removes the inode from the list
+ * and delete the memory associated to it.
+ */
+ intlist__remove(traceid_queues_list, inode);
+ }
+
+ /* Then the RB tree itself */
+ intlist__delete(traceid_queues_list);
+ etmq->traceid_queues_list = NULL;
+
+ /* finally free the traceid_queues array */
+ free(etmq->traceid_queues);
+ etmq->traceid_queues = NULL;
+}
+
static void cs_etm__free_queue(void *priv)
{
struct cs_etm_queue *etmq = priv;
@@ -419,14 +500,8 @@ static void cs_etm__free_queue(void *priv)
if (!etmq)
return;

- thread__zput(etmq->traceid_queues->thread);
cs_etm_decoder__free(etmq->decoder);
- zfree(&etmq->traceid_queues->event_buf);
- zfree(&etmq->traceid_queues->last_branch);
- zfree(&etmq->traceid_queues->last_branch_rb);
- zfree(&etmq->traceid_queues->prev_packet);
- zfree(&etmq->traceid_queues->packet);
- zfree(&etmq->traceid_queues);
+ cs_etm__free_traceid_queues(etmq);
free(etmq);
}

@@ -497,19 +572,21 @@ static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u8 trace_chan_id,
u8 cpumode;
u64 offset;
int len;
- struct thread *thread;
- struct machine *machine;
- struct addr_location al;
-
- (void)trace_chan_id;
+ struct thread *thread;
+ struct machine *machine;
+ struct addr_location al;
+ struct cs_etm_traceid_queue *tidq;

if (!etmq)
return 0;

machine = etmq->etm->machine;
cpumode = cs_etm__cpu_mode(etmq, address);
+ tidq = cs_etm__etmq_get_traceid_queue(etmq, trace_chan_id);
+ if (!tidq)
+ return 0;

- thread = etmq->traceid_queues->thread;
+ thread = tidq->thread;
if (!thread) {
if (cpumode != PERF_RECORD_MISC_KERNEL)
return 0;
@@ -545,6 +622,10 @@ static struct cs_etm_queue *cs_etm__alloc_queue(struct cs_etm_auxtrace *etm)
if (!etmq)
return NULL;

+ etmq->traceid_queues_list = intlist__new(NULL);
+ if (!etmq->traceid_queues_list)
+ goto out_free;
+
/* Use metadata to fill in trace parameters for trace decoder */
t_params = zalloc(sizeof(*t_params) * etm->num_cpu);

@@ -579,6 +660,7 @@ static struct cs_etm_queue *cs_etm__alloc_queue(struct cs_etm_auxtrace *etm)
out_free_decoder:
cs_etm_decoder__free(etmq->decoder);
out_free:
+ intlist__delete(etmq->traceid_queues_list);
free(etmq);

return NULL;
@@ -1280,8 +1362,9 @@ static bool cs_etm__is_svc_instr(struct cs_etm_queue *etmq, u8 trace_chan_id,
struct cs_etm_packet *packet,
u64 end_addr)
{
- u16 instr16;
- u32 instr32;
+ /* Initialise to keep compiler happy */
+ u16 instr16 = 0;
+ u32 instr32 = 0;
u64 addr;

switch (packet->isa) {