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Date: Tue, 14 Feb 2012 12:38:53 -0200
From: Arnaldo Carvalho de Melo <arnaldo.melo@...il.com>
To: Joerg Roedel <joerg.roedel@....com>
Cc: David Ahern <dsahern@...il.com>,
Namhyung Kim <namhyung.kim@....com>,
Namhyung Kim <namhyung@...il.com>,
linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
Andi Kleen <andi@...stfloor.org>,
Anshuman Khandual <khandual@...ux.vnet.ibm.com>,
Arun Sharma <asharma@...com>,
Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@...il.com>,
Jason Wang <jasowang@...hat.com>, Jiri Olsa <jolsa@...hat.com>,
Lin Ming <ming.m.lin@...el.com>,
Paul Mackerras <paulus@...ba.org>,
Peter Zijlstra <peterz@...radead.org>,
Roberto Agostino Vitillo <ravitillo@....gov>,
Robert Richter <robert.richter@....com>,
Stephane Eranian <eranian@...gle.com>,
Thomas Gleixner <tglx@...utronix.de>,
Vince Weaver <vweaver1@...s.utk.edu>
Subject: Re: [GIT PULL 00/16] perf/core improvements and fixes
Em Tue, Feb 14, 2012 at 11:10:46AM -0200, Arnaldo Carvalho de Melo escreveu:
> Em Tue, Feb 14, 2012 at 11:50:18AM +0100, Joerg Roedel escreveu:
> > On Mon, Feb 13, 2012 at 10:23:07PM -0700, David Ahern wrote:
> > > On 2/13/12 10:10 PM, Namhyung Kim wrote:
> > > >It happened because I used old kernel version that isn't aware of the
> > > >exclude_guest bit. So the check on attr->__reserved_1 in
> > > >core.c::perf_copy_attr() failed and then ended up seeing EINVAL at
> > > >perf_evsel__open().
>
> > > comes back to 1aed2671738785e8f5aea663a6fda91aa7ef59b5 again. See
>
> > > https://lkml.org/lkml/2012/2/8/234
>
> > Grr. I totally forgot that issue. Is there some way to detect the perf
> > kernel-features? Otherwise the only fix seems to be to drop the patch
> > changing the default. The crashes should be fixed by the other patch
> > already.
>
> Well, we need to detect it like we do with sample_id_all. In this case
> we would try with exclude_guest, if it fails with EINVAL, we realise it
> is not available, clean that bit and try again.
The following patch should fix it, still untested tho, booting a machine
with an < 3.1 kernel to check...
- Arnaldo
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 08ed24b..d6c10e8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -205,6 +205,9 @@ static void perf_record__open(struct perf_record *rec)
if (opts->group && pos != first)
group_fd = first->fd;
+fallback_missing_features:
+ if (opts->exclude_guest_missing)
+ attr->exclude_guest = attr->exclude_host = 0;
retry_sample_id:
attr->sample_id_all = opts->sample_id_all_avail ? 1 : 0;
try_again:
@@ -218,15 +221,23 @@ try_again:
} else if (err == ENODEV && opts->cpu_list) {
die("No such device - did you specify"
" an out-of-range profile CPU?\n");
- } else if (err == EINVAL && opts->sample_id_all_avail) {
- /*
- * Old kernel, no attr->sample_id_type_all field
- */
- opts->sample_id_all_avail = false;
- if (!opts->sample_time && !opts->raw_samples && !time_needed)
- attr->sample_type &= ~PERF_SAMPLE_TIME;
-
- goto retry_sample_id;
+ } else if (err == EINVAL) {
+ if (!opts->exclude_guest_missing &&
+ (attr->exclude_guest || attr->exclude_host)) {
+ pr_debug("Old kernel, cannot exclude "
+ "guest or host samples.\n");
+ opts->exclude_guest_missing = true;
+ goto fallback_missing_features;
+ } else if (opts->sample_id_all_avail) {
+ /*
+ * Old kernel, no attr->sample_id_type_all field
+ */
+ opts->sample_id_all_avail = false;
+ if (!opts->sample_time && !opts->raw_samples && !time_needed)
+ attr->sample_type &= ~PERF_SAMPLE_TIME;
+
+ goto retry_sample_id;
+ }
}
/*
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5a88c0d..02e11ff 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -872,6 +872,9 @@ static void perf_top__start_counters(struct perf_top *top)
attr->mmap = 1;
attr->comm = 1;
attr->inherit = top->inherit;
+fallback_missing_features:
+ if (top->exclude_guest_missing)
+ attr->exclude_guest = attr->exclude_host = 0;
retry_sample_id:
attr->sample_id_all = top->sample_id_all_avail ? 1 : 0;
try_again:
@@ -883,12 +886,20 @@ try_again:
if (err == EPERM || err == EACCES) {
ui__error_paranoid();
goto out_err;
- } else if (err == EINVAL && top->sample_id_all_avail) {
- /*
- * Old kernel, no attr->sample_id_type_all field
- */
- top->sample_id_all_avail = false;
- goto retry_sample_id;
+ } else if (err == EINVAL) {
+ if (!top->exclude_guest_missing &&
+ (attr->exclude_guest || attr->exclude_host)) {
+ pr_debug("Old kernel, cannot exclude "
+ "guest or host samples.\n");
+ top->exclude_guest_missing = true;
+ goto fallback_missing_features;
+ } else if (top->sample_id_all_avail) {
+ /*
+ * Old kernel, no attr->sample_id_type_all field
+ */
+ top->sample_id_all_avail = false;
+ goto retry_sample_id;
+ }
}
/*
* If it's cycles then fall back to hrtimer
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 03a0456..8b9c436 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -199,6 +199,7 @@ struct perf_record_opts {
bool sample_address;
bool sample_time;
bool sample_id_all_avail;
+ bool exclude_guest_missing;
bool system_wide;
bool period;
unsigned int freq;
diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index 49eb848..7dea891 100644
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -35,6 +35,7 @@ struct perf_top {
bool inherit;
bool group;
bool sample_id_all_avail;
+ bool exclude_guest_missing;
bool dump_symtab;
const char *cpu_list;
struct hist_entry *sym_filter_entry;
--
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