lkml.org 
[lkml]   [2016]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/urgent] perf callchain: Stop validating callchains by the max_stack sysctl
Commit-ID:  bf8bddbf1971d40549f33bc6f70623cf53bbfa2f
Gitweb: http://git.kernel.org/tip/bf8bddbf1971d40549f33bc6f70623cf53bbfa2f
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Thu, 19 May 2016 11:14:15 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Fri, 20 May 2016 11:43:56 -0300

perf callchain: Stop validating callchains by the max_stack sysctl

As thread__resolve_callchain_sample can be used for handling perf.data
files, that could've been recorded with a large max_stack sysctl setting
than what the system used for analysis has set.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/n/tip-2995bt2g5yq2m05vga4kip6m@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/machine.c | 25 +++++--------------------
1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index bdc33ce..205d270 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1771,11 +1771,6 @@ static int resolve_lbr_callchain_sample(struct thread *thread,
*/
int mix_chain_nr = i + 1 + lbr_nr + 1;

- if (mix_chain_nr > (int)sysctl_perf_event_max_stack + PERF_MAX_BRANCH_DEPTH) {
- pr_warning("corrupted callchain. skipping...\n");
- return 0;
- }
-
for (j = 0; j < mix_chain_nr; j++) {
if (callchain_param.order == ORDER_CALLEE) {
if (j < i + 1)
@@ -1815,7 +1810,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
struct ip_callchain *chain = sample->callchain;
int chain_nr = chain->nr;
u8 cpumode = PERF_RECORD_MISC_USER;
- int i, j, err, nr_entries, nr_contexts;
+ int i, j, err, nr_entries;
int skip_idx = -1;
int first_call = 0;

@@ -1830,8 +1825,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
* Based on DWARF debug information, some architectures skip
* a callchain entry saved by the kernel.
*/
- if (chain_nr < sysctl_perf_event_max_stack)
- skip_idx = arch_skip_callchain_idx(thread, chain);
+ skip_idx = arch_skip_callchain_idx(thread, chain);

/*
* Add branches to call stack for easier browsing. This gives
@@ -1891,7 +1885,7 @@ static int thread__resolve_callchain_sample(struct thread *thread,
}

check_calls:
- for (i = first_call, nr_entries = 0, nr_contexts = 0;
+ for (i = first_call, nr_entries = 0;
i < chain_nr && nr_entries < max_stack; i++) {
u64 ip;

@@ -1906,13 +1900,8 @@ check_calls:
#endif
ip = chain->ips[j];

- if (ip >= PERF_CONTEXT_MAX) {
- if (++nr_contexts > sysctl_perf_event_max_contexts_per_stack)
- goto out_corrupted_callchain;
- } else {
- if (++nr_entries > sysctl_perf_event_max_stack)
- goto out_corrupted_callchain;
- }
+ if (ip < PERF_CONTEXT_MAX)
+ ++nr_entries;

err = add_callchain_ip(thread, cursor, parent, root_al, &cpumode, ip);

@@ -1921,10 +1910,6 @@ check_calls:
}

return 0;
-
-out_corrupted_callchain:
- pr_warning("corrupted callchain. skipping...\n");
- return 0;
}

static int unwind_entry(struct unwind_entry *entry, void *arg)
\
 
 \ /
  Last update: 2016-05-20 20:01    [W:0.211 / U:0.820 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site