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 <[email protected]>
---
kernel/events/core.c | 4 ++++
tools/perf/util/event.c | 30 +++++++++++++-----------------
tools/perf/util/evsel.c | 1 -
3 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c716385..5bd7fe4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6773,6 +6773,10 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
if (ret)
return -EFAULT;
+ /* disabled for now */
+ if (attr->mmap2)
+ return -EINVAL;
+
if (attr->__reserved_1)
return -EINVAL;
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 9b393e7..63df031 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,
return -1;
}
- event->header.type = PERF_RECORD_MMAP2;
+ event->header.type = PERF_RECORD_MMAP;
/*
* Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
*/
@@ -198,7 +198,6 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
char prot[5];
char execname[PATH_MAX];
char anonstr[] = "//anon";
- unsigned int ino;
size_t size;
ssize_t n;
@@ -209,13 +208,10 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
strcpy(execname, "");
/* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */
- n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %x:%x %u %s\n",
- &event->mmap2.start, &event->mmap2.len, prot,
- &event->mmap2.pgoff, &event->mmap2.maj,
- &event->mmap2.min,
- &ino, execname);
-
- event->mmap2.ino = (u64)ino;
+ n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n",
+ &event->mmap.start, &event->mmap.len, prot,
+ &event->mmap.pgoff,
+ execname);
if (n != 8)
continue;
@@ -227,15 +223,15 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
strcpy(execname, anonstr);
size = strlen(execname) + 1;
- memcpy(event->mmap2.filename, execname, size);
+ memcpy(event->mmap.filename, execname, size);
size = PERF_ALIGN(size, sizeof(u64));
- event->mmap2.len -= event->mmap.start;
- event->mmap2.header.size = (sizeof(event->mmap2) -
- (sizeof(event->mmap2.filename) - size));
- memset(event->mmap2.filename + size, 0, machine->id_hdr_size);
- event->mmap2.header.size += machine->id_hdr_size;
- event->mmap2.pid = tgid;
- event->mmap2.tid = pid;
+ event->mmap.len -= event->mmap.start;
+ event->mmap.header.size = (sizeof(event->mmap) -
+ (sizeof(event->mmap.filename) - size));
+ memset(event->mmap.filename + size, 0, machine->id_hdr_size);
+ event->mmap.header.size += machine->id_hdr_size;
+ event->mmap.pid = tgid;
+ event->mmap.tid = pid;
if (process(tool, event, &synth_sample, machine) != 0) {
rc = -1;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index bfebc1e..bab6775 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,
attr->sample_type |= PERF_SAMPLE_WEIGHT;
attr->mmap = track;
- attr->mmap2 = track && !perf_missing_features.mmap2;
attr->comm = track;
if (opts->sample_transaction)
--
1.7.9.5
Em Thu, Oct 17, 2013 at 07:32:15PM +0200, Stephane Eranian escreveu:
>
> 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.
Again it applied, but with some fuzz, which branch did you coded this
against? Testing...
[acme@zoo linux]$ patch -p1 < /wb/1
patching file kernel/events/core.c
Hunk #1 succeeded at 6767 (offset -6 lines).
patching file tools/perf/util/event.c
patching file tools/perf/util/evsel.c
Hunk #1 succeeded at 678 with fuzz 1.
[acme@zoo linux]$
- Arnaldo
Commit-ID: 3090ffb5a2515990182f3f55b0688a7817325488
Gitweb: http://git.kernel.org/tip/3090ffb5a2515990182f3f55b0688a7817325488
Author: Stephane Eranian <[email protected]>
AuthorDate: Thu, 17 Oct 2013 19:32:15 +0200
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Thu, 17 Oct 2013 16:27:14 -0300
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 <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/20131017173215.GA8820@quad
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
kernel/events/core.c | 4 ++++
tools/perf/util/event.c | 30 +++++++++++++-----------------
tools/perf/util/evsel.c | 1 -
3 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index d49a9d2..953c143 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,
if (ret)
return -EFAULT;
+ /* disabled for now */
+ if (attr->mmap2)
+ return -EINVAL;
+
if (attr->__reserved_1)
return -EINVAL;
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 9b393e7..63df031 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,
return -1;
}
- event->header.type = PERF_RECORD_MMAP2;
+ event->header.type = PERF_RECORD_MMAP;
/*
* Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
*/
@@ -198,7 +198,6 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
char prot[5];
char execname[PATH_MAX];
char anonstr[] = "//anon";
- unsigned int ino;
size_t size;
ssize_t n;
@@ -209,13 +208,10 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
strcpy(execname, "");
/* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */
- n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %x:%x %u %s\n",
- &event->mmap2.start, &event->mmap2.len, prot,
- &event->mmap2.pgoff, &event->mmap2.maj,
- &event->mmap2.min,
- &ino, execname);
-
- event->mmap2.ino = (u64)ino;
+ n = sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n",
+ &event->mmap.start, &event->mmap.len, prot,
+ &event->mmap.pgoff,
+ execname);
if (n != 8)
continue;
@@ -227,15 +223,15 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
strcpy(execname, anonstr);
size = strlen(execname) + 1;
- memcpy(event->mmap2.filename, execname, size);
+ memcpy(event->mmap.filename, execname, size);
size = PERF_ALIGN(size, sizeof(u64));
- event->mmap2.len -= event->mmap.start;
- event->mmap2.header.size = (sizeof(event->mmap2) -
- (sizeof(event->mmap2.filename) - size));
- memset(event->mmap2.filename + size, 0, machine->id_hdr_size);
- event->mmap2.header.size += machine->id_hdr_size;
- event->mmap2.pid = tgid;
- event->mmap2.tid = pid;
+ event->mmap.len -= event->mmap.start;
+ event->mmap.header.size = (sizeof(event->mmap) -
+ (sizeof(event->mmap.filename) - size));
+ memset(event->mmap.filename + size, 0, machine->id_hdr_size);
+ event->mmap.header.size += machine->id_hdr_size;
+ event->mmap.pid = tgid;
+ event->mmap.tid = pid;
if (process(tool, event, &synth_sample, machine) != 0) {
rc = -1;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 0ce9feb..9f1ef9b 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,
attr->sample_type |= PERF_SAMPLE_WEIGHT;
attr->mmap = track;
- attr->mmap2 = track && !perf_missing_features.mmap2;
attr->comm = track;
/*