i2p/haiku-beta6
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Solution for the potential deadlock when needing to flush the profiling

Browse Source 
buffer during a timer event that interrupted a kernel function: We do
now flush the buffer as soon as it is 70% full, *if* we didn't interrupt
a kernel function. When the buffer runs full and we still haven't hit a
user function, we drop the tick. The number of dropped ticks is recorded
and sent to the debugger with the next update message.
Reverted the previous partial solution (the temporary disabling of
profiling while in debugger support code).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27658 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Ingo Weinhold
2008-09-20 22:04:03 +00:00
parent 1ecc0a33db
commit ecfad924e0
3 changed files with 40 additions and 73 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/system/kernel/debug/user_debugger.cpp
+28 -68
View File
@@ -54,51 +54,6 @@ static status_t ensure_debugger_installed(team_id teamID, port_id *port = NULL);
static void get_team_debug_info(team_debug_info &teamDebugInfo);
static void
enable_profiling()
{
struct thread* thread = thread_get_current_thread();
InterruptsSpinLocker _(gThreadSpinlock);
if (--thread->debug_info.profile.disabled > 0)
return;
if (thread->debug_info.profile.samples != NULL
&& !thread->debug_info.profile.buffer_full) {
// install profiling timer
schedule_profiling_timer(thread,
thread->debug_info.profile.interval_left);
}
}
static void
disable_profiling()
{
struct thread* thread = thread_get_current_thread();
InterruptsSpinLocker _(gThreadSpinlock);
if (thread->debug_info.profile.disabled++ > 0) {
ASSERT(thread->debug_info.profile.installed_timer == NULL);
return;
}
// if running, cancel the profiling timer
struct timer* timer = thread->debug_info.profile.installed_timer;
if (timer != NULL) {
// track remaining time
bigtime_t left = thread->debug_info.profile.timer_end - system_time();
thread->debug_info.profile.interval_left = max_c(left, 0);
thread->debug_info.profile.installed_timer = NULL;
// cancel timer
cancel_timer(timer);
}
}
static status_t
kill_interruptable_write_port(port_id port, int32 code, const void *buffer,
size_t bufferSize)
@@ -119,8 +74,6 @@ debugger_write(port_id port, int32 code, const void *buffer, size_t bufferSize,
status_t error = B_OK;
disable_profiling();
// get the team debug info
team_debug_info teamDebugInfo;
get_team_debug_info(teamDebugInfo);
@@ -132,7 +85,6 @@ debugger_write(port_id port, int32 code, const void *buffer, size_t bufferSize,
dontWait ? (uint32)B_RELATIVE_TIMEOUT : (uint32)B_KILL_CAN_INTERRUPT, 0);
if (error != B_OK) {
TRACE(("debugger_write() done1: %lx\n", error));
enable_profiling();
return error;
}
@@ -159,7 +111,6 @@ debugger_write(port_id port, int32 code, const void *buffer, size_t bufferSize,
TRACE(("debugger_write() done: %lx\n", error));
enable_profiling();
return error;
}
@@ -337,7 +288,6 @@ init_thread_debug_info(struct thread_debug_info *info)
info->ignore_signals_once = 0;
info->profile.sample_area = -1;
info->profile.samples = NULL;
info->profile.disabled = 0;
info->profile.buffer_full = false;
info->profile.installed_timer = NULL;
}
@@ -364,7 +314,6 @@ clear_thread_debug_info(struct thread_debug_info *info, bool dying)
info->ignore_signals_once = 0;
info->profile.sample_area = -1;
info->profile.samples = NULL;
info->profile.disabled = 0;
info->profile.buffer_full = false;
}
}
@@ -735,8 +684,6 @@ static status_t
thread_hit_debug_event(debug_debugger_message event, const void *message,
int32 size, bool requireDebugger)
{
disable_profiling();
status_t result;
bool restart;
do {
@@ -745,8 +692,6 @@ thread_hit_debug_event(debug_debugger_message event, const void *message,
requireDebugger, restart);
} while (result >= 0 && restart);
enable_profiling();
return result;
}
@@ -1082,11 +1027,11 @@ user_debug_thread_exiting(struct thread* thread)
area_id sampleArea = threadDebugInfo.profile.sample_area;
int32 sampleCount = threadDebugInfo.profile.sample_count;
int32 droppedTicks = threadDebugInfo.profile.dropped_ticks;
int32 stackDepth = threadDebugInfo.profile.stack_depth;
int32 imageEvent = threadDebugInfo.profile.image_event;
threadDebugInfo.profile.sample_area = -1;
threadDebugInfo.profile.samples = NULL;
threadDebugInfo.profile.disabled = 0;
threadDebugInfo.profile.buffer_full = false;
atomic_or(&threadDebugInfo.flags, B_THREAD_DEBUG_DYING);
@@ -1100,6 +1045,7 @@ user_debug_thread_exiting(struct thread* thread)
message.origin.team = thread->team->id;
message.origin.nub_port = -1; // asynchronous message
message.sample_count = sampleCount;
message.dropped_ticks = droppedTicks;
message.stack_depth = stackDepth;
message.image_event = imageEvent;
message.stopped = true;
@@ -1254,9 +1200,19 @@ profiling_do_sample(bool& flushBuffer)
int32 imageEvent = thread->team->debug_info.image_event;
if (debugInfo.profile.sample_count > 0) {
if (debugInfo.profile.image_event < imageEvent
|| debugInfo.profile.max_samples - sampleCount < stackDepth) {
flushBuffer = true;
return true;
|| debugInfo.profile.flush_threshold - sampleCount < stackDepth) {
if (!IS_KERNEL_ADDRESS(arch_debug_get_interrupt_pc())) {
flushBuffer = true;
return true;
}
// We can't flush the buffer now, since we interrupted a kernel
// function. If the buffer is not full yet, we add the samples,
// otherwise we have to drop them.
if (debugInfo.profile.max_samples - sampleCount < stackDepth) {
debugInfo.profile.dropped_ticks++;
return true;
}
}
} else {
// first sample -- set the image event
@@ -1291,11 +1247,13 @@ profiling_buffer_full(void*)
if (debugInfo.profile.samples != NULL && debugInfo.profile.buffer_full) {
int32 sampleCount = debugInfo.profile.sample_count;
int32 droppedTicks = debugInfo.profile.dropped_ticks;
int32 stackDepth = debugInfo.profile.stack_depth;
int32 imageEvent = debugInfo.profile.image_event;
// notify the debugger
debugInfo.profile.sample_count = 0;
debugInfo.profile.dropped_ticks = 0;
RELEASE_THREAD_LOCK();
enable_interrupts();
@@ -1303,6 +1261,7 @@ profiling_buffer_full(void*)
// prepare the message
debug_profiler_update message;
message.sample_count = sampleCount;
message.dropped_ticks = droppedTicks;
message.stack_depth = stackDepth;
message.image_event = imageEvent;
message.stopped = false;
@@ -1333,7 +1292,7 @@ profiling_event(timer* /*unused*/)
struct thread* thread = thread_get_current_thread();
thread_debug_info& debugInfo = thread->debug_info;
bool flushBuffer;
bool flushBuffer = false;
if (profiling_do_sample(flushBuffer)) {
if (flushBuffer) {
// The sample buffer needs to be flushed; we'll have to notify the
@@ -1355,11 +1314,6 @@ profiling_event(timer* /*unused*/)
void
user_debug_thread_unscheduled(struct thread* thread)
{
if (thread->debug_info.profile.disabled > 0) {
ASSERT(thread->debug_info.profile.installed_timer == NULL);
return;
}
// if running, cancel the profiling timer
struct timer* timer = thread->debug_info.profile.installed_timer;
if (timer != NULL) {
@@ -1377,9 +1331,6 @@ user_debug_thread_unscheduled(struct thread* thread)
void
user_debug_thread_scheduled(struct thread* thread)
{
if (thread->debug_info.profile.disabled > 0)
return;
if (thread->debug_info.profile.samples != NULL
&& !thread->debug_info.profile.buffer_full) {
// install profiling timer
@@ -2321,7 +2272,12 @@ debug_nub_thread(void *)
threadDebugInfo.profile.samples = (addr_t*)samples;
threadDebugInfo.profile.max_samples
= areaInfo.size / sizeof(addr_t);
threadDebugInfo.profile.flush_threshold
= threadDebugInfo.profile.max_samples
* B_DEBUG_PROFILE_BUFFER_FLUSH_THRESHOLD
/ 100;
threadDebugInfo.profile.sample_count = 0;
threadDebugInfo.profile.dropped_ticks = 0;
threadDebugInfo.profile.stack_depth = stackDepth;
threadDebugInfo.profile.buffer_full = false;
threadDebugInfo.profile.interval_left = interval;
@@ -2369,6 +2325,7 @@ debug_nub_thread(void *)
int32 sampleCount = 0;
int32 stackDepth = 0;
int32 imageEvent = 0;
int32 droppedTicks = 0;
// get the thread and detach the profile info
cpu_status state = disable_interrupts();
@@ -2382,11 +2339,13 @@ debug_nub_thread(void *)
sampleArea = threadDebugInfo.profile.sample_area;
samples = threadDebugInfo.profile.samples;
sampleCount = threadDebugInfo.profile.sample_count;
droppedTicks = threadDebugInfo.profile.dropped_ticks;
stackDepth = threadDebugInfo.profile.stack_depth;
imageEvent = threadDebugInfo.profile.image_event;
threadDebugInfo.profile.sample_area = -1;
threadDebugInfo.profile.samples = NULL;
threadDebugInfo.profile.buffer_full = false;
threadDebugInfo.profile.dropped_ticks = 0;
} else
result = B_BAD_VALUE;
} else
@@ -2401,6 +2360,7 @@ debug_nub_thread(void *)
reply.profiler_update.image_event = imageEvent;
reply.profiler_update.stack_depth = stackDepth;
reply.profiler_update.sample_count = sampleCount;
reply.profiler_update.dropped_ticks = droppedTicks;
reply.profiler_update.stopped = true;
} else
reply.profiler_update.origin.thread = result;