From 29e2616aeeb82605a6efe1dbc574b499781eafbe Mon Sep 17 00:00:00 2001 From: Josh Stone Date: Wed, 20 May 2009 14:46:25 -0700 Subject: PR10177: init/kill time in sleepy context only Previously, _stp_init_time and _stp_kill_time were being called from begin/end/error probes, which will run with preemption disabled. The BUG reported on RT kernels showed that cpufreq_unregister_notifier can end up sleeping, which violates our preemption block. This patch moves the init/kill into systemtap_module_init/exit, where it is safe to sleep. The code maintains a new predicate with the define STAP_NEED_GETTIMEOFDAY, so we don't still incur any timer overhead if it's not used. --- translate.cxx | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'translate.cxx') diff --git a/translate.cxx b/translate.cxx index 62c71aeb..9f45f5d1 100644 --- a/translate.cxx +++ b/translate.cxx @@ -1133,6 +1133,15 @@ c_unparser::emit_module_init () o->newline(-1) << "}"; o->newline() << "if (rc) goto out;"; + // initialize gettimeofday (if needed) + o->newline() << "#ifdef STAP_NEED_GETTIMEOFDAY"; + o->newline() << "rc = _stp_init_time();"; // Kick off the Big Bang. + o->newline() << "if (rc) {"; + o->newline(1) << "_stp_error (\"couldn't initialize gettimeofday\");"; + o->newline() << "goto out;"; + o->newline(-1) << "}"; + o->newline() << "#endif"; + o->newline() << "(void) probe_point;"; o->newline() << "(void) i;"; o->newline() << "(void) j;"; @@ -1359,6 +1368,11 @@ c_unparser::emit_module_exit () o->newline() << "#endif"; } + // teardown gettimeofday (if needed) + o->newline() << "#ifdef STAP_NEED_GETTIMEOFDAY"; + o->newline() << " _stp_kill_time();"; // Go to a beach. Drink a beer. + o->newline() << "#endif"; + // print final error/skipped counts if non-zero o->newline() << "if (atomic_read (& skipped_count) || " << "atomic_read (& error_count) || " -- cgit