Ian came with the idea of having support to read the pipe data also from
file. Currently pipe mode files fail like:
$ perf record -o - sleep 1 > /tmp/perf.pipe.data
$ perf report -i /tmp/perf.pipe.data
incompatible file format (rerun with -v to learn more)
This patch adds the support to do that by trying the pipe header first,
and if its successfully detected, switching the perf data to pipe mode.
Committer testing:
# ls
# perf record -a -o - sleep 1 > /tmp/perf.pipe.data
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.000 MB - ]
# ls
# perf report -i /tmp/perf.pipe.data | head -25
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 511 of event 'cycles'
# Event count (approx.):
178447276
#
# Overhead Command Shared Object Symbol
# ........ ........ ................. ...........................................................................................
#
65.49% swapper [kernel.kallsyms] [k] native_safe_halt
6.45% chromium libblink_core.so [.] blink::SelectorChecker::CheckOne
4.08% chromium libblink_core.so [.] blink::SelectorQuery::ExecuteForTraverseRoot<blink::AllElementsSelectorQueryTrait>
2.25% chromium libblink_core.so [.] blink::SelectorQuery::FindTraverseRootsAndExecute<blink::AllElementsSelectorQueryTrait>
2.11% chromium libblink_core.so [.] blink::SelectorChecker::MatchSelector
1.91% chromium libblink_core.so [.] blink::Node::OwnerShadowHost
1.31% chromium libblink_core.so [.] blink::Node::parentNode@plt
1.22% chromium libblink_core.so [.] blink::Node::parentNode
0.59% chromium libblink_core.so [.] blink::AnyAttributeMatches
0.58% chromium libv8.so [.] v8::internal::GlobalHandles::Create
0.58% chromium libblink_core.so [.] blink::NodeTraversal::NextAncestorSibling
0.55% chromium libv8.so [.] v8::internal::RegExpGlobalCache::RegExpGlobalCache
0.55% chromium libblink_core.so [.] blink::Node::ContainingShadowRoot
0.55% chromium libblink_core.so [.] blink::NodeTraversal::NextAncestorSibling@plt
#
Original-patch-by: Ian Rogers <irogers@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Khuong <pvk@pvk.ca>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200507095024.2789147-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
return -EINVAL;
}
- return 0;
+ return f_header.size == sizeof(f_header) ? 0 : -1;
}
static int read_attr(int fd, struct perf_header *ph,
struct perf_file_header f_header;
struct perf_file_attr f_attr;
u64 f_id;
- int nr_attrs, nr_ids, i, j;
+ int nr_attrs, nr_ids, i, j, err;
int fd = perf_data__fd(data);
session->evlist = evlist__new();
session->evlist->env = &header->env;
session->machines.host.env = &header->env;
- if (perf_data__is_pipe(data))
- return perf_header__read_pipe(session);
+
+ /*
+ * We can read 'pipe' data event from regular file,
+ * check for the pipe header regardless of source.
+ */
+ err = perf_header__read_pipe(session);
+ if (!err || (err && perf_data__is_pipe(data))) {
+ data->is_pipe = true;
+ return err;
+ }
if (perf_file_header__read(&f_header, header, fd) < 0)
return -EINVAL;