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authorStephane Eranian <eranian@google.com>2013-10-17 13:32:15 -0400
committerArnaldo Carvalho de Melo <acme@redhat.com>2013-10-17 15:27:14 -0400
commit3090ffb5a2515990182f3f55b0688a7817325488 (patch)
treea867d484f48cd124f3333ee6d10b120d2b9ac784
parent3b16ff89676d9902dc39976aee3cb0314ee37d93 (diff)
perf: Disable PERF_RECORD_MMAP2 support
For now, we disable the extended MMAP record support (MMAP2). We have identified cases where it would not report the correct mapping information, clone(VM_CLONE) but with separate pids. We will revisit the support once we find a solution for this case. The patch changes the kernel to return EINVAL if attr->mmap2 is set. The patch also modifies the perf tool to use regular PERF_RECORD_MMAP for synthetic events and it also prevents the tool from requesting attr->mmap2 mode because the kernel would reject it. The support will be revisited once the kenrel interface is updated. In V2, we reduce the patch to the strict minimum. In V3, we avoid calling perf_event_open() with mmap2 set because we know it will fail and require fallback retry. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131017173215.GA8820@quad Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-rw-r--r--kernel/events/core.c4
-rw-r--r--tools/perf/util/event.c30
-rw-r--r--tools/perf/util/evsel.c1
3 files changed, 17 insertions, 18 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d49a9d29334c..953c14348375 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6767,6 +6767,10 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
6767 if (ret) 6767 if (ret)
6768 return -EFAULT; 6768 return -EFAULT;
6769 6769
6770 /* disabled for now */
6771 if (attr->mmap2)
6772 return -EINVAL;
6773
6770 if (attr->__reserved_1) 6774 if (attr->__reserved_1)
6771 return -EINVAL; 6775 return -EINVAL;
6772 6776
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 9b393e7dca6f..63df031fc9c7 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -187,7 +187,7 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
187 return -1; 187 return -1;
188 } 188 }
189 189
190 event->header.type = PERF_RECORD_MMAP2; 190 event->header.type = PERF_RECORD_MMAP;
191 /* 191 /*
192 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c 192 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
193 */ 193 */
@@ -198,7 +198,6 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
198 char prot[5]; 198 char prot[5];
199 char execname[PATH_MAX]; 199 char execname[PATH_MAX];
200 char anonstr[] = "//anon"; 200 char anonstr[] = "//anon";
201 unsigned int ino;
202 size_t size; 201 size_t size;
203 ssize_t n; 202 ssize_t n;
204 203
@@ -209,13 +208,10 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
209 strcpy(execname, ""); 208 strcpy(execname, "");
210 209
211 /* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */ 210 /* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */
212 n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %x:%x %u %s\n", 211 n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n",
213 &event->mmap2.start, &event->mmap2.len, prot, 212 &event->mmap.start, &event->mmap.len, prot,
214 &event->mmap2.pgoff, &event->mmap2.maj, 213 &event->mmap.pgoff,
215 &event->mmap2.min, 214 execname);
216 &ino, execname);
217
218 event->mmap2.ino = (u64)ino;
219 215
220 if (n != 8) 216 if (n != 8)
221 continue; 217 continue;
@@ -227,15 +223,15 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
227 strcpy(execname, anonstr); 223 strcpy(execname, anonstr);
228 224
229 size = strlen(execname) + 1; 225 size = strlen(execname) + 1;
230 memcpy(event->mmap2.filename, execname, size); 226 memcpy(event->mmap.filename, execname, size);
231 size = PERF_ALIGN(size, sizeof(u64)); 227 size = PERF_ALIGN(size, sizeof(u64));
232 event->mmap2.len -= event->mmap.start; 228 event->mmap.len -= event->mmap.start;
233 event->mmap2.header.size = (sizeof(event->mmap2) - 229 event->mmap.header.size = (sizeof(event->mmap) -
234 (sizeof(event->mmap2.filename) - size)); 230 (sizeof(event->mmap.filename) - size));
235 memset(event->mmap2.filename + size, 0, machine->id_hdr_size); 231 memset(event->mmap.filename + size, 0, machine->id_hdr_size);
236 event->mmap2.header.size += machine->id_hdr_size; 232 event->mmap.header.size += machine->id_hdr_size;
237 event->mmap2.pid = tgid; 233 event->mmap.pid = tgid;
238 event->mmap2.tid = pid; 234 event->mmap.tid = pid;
239 235
240 if (process(tool, event, &synth_sample, machine) != 0) { 236 if (process(tool, event, &synth_sample, machine) != 0) {
241 rc = -1; 237 rc = -1;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0ce9febf1ba0..9f1ef9bee2d0 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -678,7 +678,6 @@ void perf_evsel__config(struct perf_evsel *evsel,
678 attr->sample_type |= PERF_SAMPLE_WEIGHT; 678 attr->sample_type |= PERF_SAMPLE_WEIGHT;
679 679
680 attr->mmap = track; 680 attr->mmap = track;
681 attr->mmap2 = track && !perf_missing_features.mmap2;
682 attr->comm = track; 681 attr->comm = track;
683 682
684 /* 683 /*