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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-25 17:05:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-25 17:05:40 -0700
commitbdc6b758e443c21c39a14c075e5b7e01f095b37b (patch)
tree40b98b5abd501cc232f41af03eb078282d7a6327 /tools/perf/builtin-record.c
parentc4a346002bc06046bc51910a7ade3a0c650c3d34 (diff)
parent0c9f790fcbdaf8cfb6dd7fb4e88fadf55082e37e (diff)
downloadlinux-bdc6b758e443c21c39a14c075e5b7e01f095b37b.tar.gz
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar: "Mostly tooling and PMU driver fixes, but also a number of late updates such as the reworking of the call-chain size limiting logic to make call-graph recording more robust, plus tooling side changes for the new 'backwards ring-buffer' extension to the perf ring-buffer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) perf record: Read from backward ring buffer perf record: Rename variable to make code clear perf record: Prevent reading invalid data in record__mmap_read perf evlist: Add API to pause/resume perf trace: Use the ptr->name beautifier as default for "filename" args perf trace: Use the fd->name beautifier as default for "fd" args perf report: Add srcline_from/to branch sort keys perf evsel: Record fd into perf_mmap perf evsel: Add overwrite attribute and check write_backward perf tools: Set buildid dir under symfs when --symfs is provided perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced perf annotate: Sort list of recognised instructions perf annotate: Fix identification of ARM blt and bls instructions perf tools: Fix usage of max_stack sysctl perf callchain: Stop validating callchains by the max_stack sysctl perf trace: Fix exit_group() formatting perf top: Use machine->kptr_restrict_warned perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1 perf machine: Do not bail out if not managing to read ref reloc symbol perf/x86/intel/p4: Trival indentation fix, remove space ...
Diffstat (limited to 'tools/perf/builtin-record.c')
-rw-r--r--tools/perf/builtin-record.c81
1 files changed, 71 insertions, 10 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f3679c44d3f3..dc3fcb597e4c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -40,6 +40,7 @@
#include <unistd.h>
#include <sched.h>
#include <sys/mman.h>
+#include <asm/bug.h>
struct record {
@@ -82,27 +83,87 @@ static int process_synthesized_event(struct perf_tool *tool,
return record__write(rec, event, event->header.size);
}
+static int
+backward_rb_find_range(void *buf, int mask, u64 head, u64 *start, u64 *end)
+{
+ struct perf_event_header *pheader;
+ u64 evt_head = head;
+ int size = mask + 1;
+
+ pr_debug2("backward_rb_find_range: buf=%p, head=%"PRIx64"\n", buf, head);
+ pheader = (struct perf_event_header *)(buf + (head & mask));
+ *start = head;
+ while (true) {
+ if (evt_head - head >= (unsigned int)size) {
+ pr_debug("Finshed reading backward ring buffer: rewind\n");
+ if (evt_head - head > (unsigned int)size)
+ evt_head -= pheader->size;
+ *end = evt_head;
+ return 0;
+ }
+
+ pheader = (struct perf_event_header *)(buf + (evt_head & mask));
+
+ if (pheader->size == 0) {
+ pr_debug("Finshed reading backward ring buffer: get start\n");
+ *end = evt_head;
+ return 0;
+ }
+
+ evt_head += pheader->size;
+ pr_debug3("move evt_head: %"PRIx64"\n", evt_head);
+ }
+ WARN_ONCE(1, "Shouldn't get here\n");
+ return -1;
+}
+
+static int
+rb_find_range(struct perf_evlist *evlist,
+ void *data, int mask, u64 head, u64 old,
+ u64 *start, u64 *end)
+{
+ if (!evlist->backward) {
+ *start = old;
+ *end = head;
+ return 0;
+ }
+
+ return backward_rb_find_range(data, mask, head, start, end);
+}
+
static int record__mmap_read(struct record *rec, int idx)
{
struct perf_mmap *md = &rec->evlist->mmap[idx];
u64 head = perf_mmap__read_head(md);
u64 old = md->prev;
+ u64 end = head, start = old;
unsigned char *data = md->base + page_size;
unsigned long size;
void *buf;
int rc = 0;
- if (old == head)
+ if (rb_find_range(rec->evlist, data, md->mask, head,
+ old, &start, &end))
+ return -1;
+
+ if (start == end)
return 0;
rec->samples++;
- size = head - old;
+ size = end - start;
+ if (size > (unsigned long)(md->mask) + 1) {
+ WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
+
+ md->prev = head;
+ perf_evlist__mmap_consume(rec->evlist, idx);
+ return 0;
+ }
- if ((old & md->mask) + size != (head & md->mask)) {
- buf = &data[old & md->mask];
- size = md->mask + 1 - (old & md->mask);
- old += size;
+ if ((start & md->mask) + size != (end & md->mask)) {
+ buf = &data[start & md->mask];
+ size = md->mask + 1 - (start & md->mask);
+ start += size;
if (record__write(rec, buf, size) < 0) {
rc = -1;
@@ -110,16 +171,16 @@ static int record__mmap_read(struct record *rec, int idx)
}
}
- buf = &data[old & md->mask];
- size = head - old;
- old += size;
+ buf = &data[start & md->mask];
+ size = end - start;
+ start += size;
if (record__write(rec, buf, size) < 0) {
rc = -1;
goto out;
}
- md->prev = old;
+ md->prev = head;
perf_evlist__mmap_consume(rec->evlist, idx);
out:
return rc;