<div dir="ltr">Oops -- thanks Bill, sorry I missed this email. I'll go fix.</div><br><div class="gmail_quote"><div dir="ltr">On Tue, Apr 11, 2017 at 6:32 AM Bill Seurer <<a href="mailto:seurer@linux.vnet.ibm.com">seurer@linux.vnet.ibm.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">If clang is used to compile and the build is set up with<br class="gmail_msg">
-DLLVM_ENABLE_WERROR=ON this change generates errors, at least on<br class="gmail_msg">
powerpc LE.<br class="gmail_msg">
<br class="gmail_msg">
(See for example<br class="gmail_msg">
<a href="http://lab.llvm.org:8011/builders/sanitizer-ppc64le-linux/builds/1983/steps/build%20with%20ninja/logs/stdio" rel="noreferrer" class="gmail_msg" target="_blank">http://lab.llvm.org:8011/builders/sanitizer-ppc64le-linux/builds/1983/steps/build%20with%20ninja/logs/stdio</a>)<br class="gmail_msg">
<br class="gmail_msg">
<br class="gmail_msg">
FAILED:<br class="gmail_msg">
projects/compiler-rt/lib/xray/tests/unit/CMakeFiles/xray_fdr_log_printer.dir/xray_fdr_log_printer_tool.cc.o<br class="gmail_msg">
<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/clang_build/bin/clang++<br class="gmail_msg">
-DLLVM_BUILD_GLOBAL_ISEL -D_DEBUG -D_GNU_SOURCE<br class="gmail_msg">
-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS<br class="gmail_msg">
-Iprojects/compiler-rt/lib/xray/tests/unit<br class="gmail_msg">
-I/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/tests/unit<br class="gmail_msg">
-Iinclude<br class="gmail_msg">
-I/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/include<br class="gmail_msg">
-I/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/..<br class="gmail_msg">
-I/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../../include<br class="gmail_msg">
-I/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/tests/..<br class="gmail_msg">
-gmlt -fPIC -fvisibility-inlines-hidden -Werror -Werror=date-time<br class="gmail_msg">
-std=c++11 -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual<br class="gmail_msg">
-Wmissing-field-initializers -pedantic -Wno-long-long<br class="gmail_msg">
-Wcovered-switch-default -Wnon-virtual-dtor -Wdelete-non-virtual-dtor<br class="gmail_msg">
-Wstring-conversion -fcolor-diagnostics -ffunction-sections<br class="gmail_msg">
-fdata-sections -Wall -Werror -std=c++11 -Wno-unused-parameter -O3<br class="gmail_msg">
-UNDEBUG -MMD -MT<br class="gmail_msg">
projects/compiler-rt/lib/xray/tests/unit/CMakeFiles/xray_fdr_log_printer.dir/xray_fdr_log_printer_tool.cc.o<br class="gmail_msg">
-MF<br class="gmail_msg">
projects/compiler-rt/lib/xray/tests/unit/CMakeFiles/xray_fdr_log_printer.dir/xray_fdr_log_printer_tool.cc.o.d<br class="gmail_msg">
-o<br class="gmail_msg">
projects/compiler-rt/lib/xray/tests/unit/CMakeFiles/xray_fdr_log_printer.dir/xray_fdr_log_printer_tool.cc.o<br class="gmail_msg">
-c<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/tests/unit/xray_fdr_log_printer_tool.cc<br class="gmail_msg">
In file included from<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/tests/unit/xray_fdr_log_printer_tool.cc:15:<br class="gmail_msg">
In file included from<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/tests/../xray_fdr_logging_impl.h:35:<br class="gmail_msg">
In file included from<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/tests/../xray_flags.h:18:<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:23:7:<br class="gmail_msg">
error: '__sanitizer::FlagHandlerBase' has virtual functions but<br class="gmail_msg">
non-virtual destructor [-Werror,-Wnon-virtual-dtor]<br class="gmail_msg">
class FlagHandlerBase {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:29:7:<br class="gmail_msg">
error: '__sanitizer::FlagHandler<bool>' has virtual functions but<br class="gmail_msg">
non-virtual destructor [-Werror,-Wnon-virtual-dtor]<br class="gmail_msg">
class FlagHandler : public FlagHandlerBase {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:38:13:<br class="gmail_msg">
note: in instantiation of template class<br class="gmail_msg">
'__sanitizer::FlagHandler<bool>' requested here<br class="gmail_msg">
inline bool FlagHandler<bool>::Parse(const char *value) {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:29:7:<br class="gmail_msg">
error: '__sanitizer::FlagHandler<const char *>' has virtual functions<br class="gmail_msg">
but non-virtual destructor [-Werror,-Wnon-virtual-dtor]<br class="gmail_msg">
class FlagHandler : public FlagHandlerBase {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:56:13:<br class="gmail_msg">
note: in instantiation of template class '__sanitizer::FlagHandler<const<br class="gmail_msg">
char *>' requested here<br class="gmail_msg">
inline bool FlagHandler<const char *>::Parse(const char *value) {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:29:7:<br class="gmail_msg">
error: '__sanitizer::FlagHandler<int>' has virtual functions but<br class="gmail_msg">
non-virtual destructor [-Werror,-Wnon-virtual-dtor]<br class="gmail_msg">
class FlagHandler : public FlagHandlerBase {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:62:13:<br class="gmail_msg">
note: in instantiation of template class '__sanitizer::FlagHandler<int>'<br class="gmail_msg">
requested here<br class="gmail_msg">
inline bool FlagHandler<int>::Parse(const char *value) {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:29:7:<br class="gmail_msg">
error: '__sanitizer::FlagHandler<unsigned long>' has virtual functions<br class="gmail_msg">
but non-virtual destructor [-Werror,-Wnon-virtual-dtor]<br class="gmail_msg">
class FlagHandler : public FlagHandlerBase {<br class="gmail_msg">
^<br class="gmail_msg">
/home/buildbots/ppc64le-sanitizer/sanitizer-ppc64le/build/llvm/projects/compiler-rt/lib/xray/../sanitizer_common/sanitizer_flag_parser.h:71:13:<br class="gmail_msg">
note: in instantiation of template class<br class="gmail_msg">
'__sanitizer::FlagHandler<unsigned long>' requested here<br class="gmail_msg">
inline bool FlagHandler<uptr>::Parse(const char *value) {<br class="gmail_msg">
^<br class="gmail_msg">
5 errors generated.<br class="gmail_msg">
<br class="gmail_msg">
<br class="gmail_msg">
<br class="gmail_msg">
On 04/06/2017 02:14 AM, Dean Michael Berris via llvm-commits wrote:<br class="gmail_msg">
> Author: dberris<br class="gmail_msg">
> Date: Thu Apr 6 02:14:43 2017<br class="gmail_msg">
> New Revision: 299629<br class="gmail_msg">
><br class="gmail_msg">
> URL: <a href="http://llvm.org/viewvc/llvm-project?rev=299629&view=rev" rel="noreferrer" class="gmail_msg" target="_blank">http://llvm.org/viewvc/llvm-project?rev=299629&view=rev</a><br class="gmail_msg">
> Log:<br class="gmail_msg">
> [XRay] [compiler-rt] Unwriting FDR mode buffers when functions are short.<br class="gmail_msg">
><br class="gmail_msg">
> Summary:<br class="gmail_msg">
> "short" is defined as an xray flag, and buffer rewinding happens for both exits<br class="gmail_msg">
> and tail exits.<br class="gmail_msg">
><br class="gmail_msg">
> I've made the choice to seek backwards finding pairs of FunctionEntry, TailExit<br class="gmail_msg">
> record pairs and erasing them if the FunctionEntry occurred before exit from the<br class="gmail_msg">
> currently exiting function. This is a compromise so that we don't skip logging<br class="gmail_msg">
> tail calls if the function that they call into takes longer our duration.<br class="gmail_msg">
><br class="gmail_msg">
> This works by counting the consecutive function and function entry, tail exit<br class="gmail_msg">
> pairs that proceed the current point in the buffer. The buffer is rewound to<br class="gmail_msg">
> check whether these entry points happened recently enough to be erased.<br class="gmail_msg">
><br class="gmail_msg">
> It is still possible we will omit them if they call into a child function that<br class="gmail_msg">
> is not instrumented which calls a fast grandchild that is instrumented before<br class="gmail_msg">
> doing other processing.<br class="gmail_msg">
><br class="gmail_msg">
> Reviewers: pelikan, dberris<br class="gmail_msg">
><br class="gmail_msg">
> Reviewed By: dberris<br class="gmail_msg">
><br class="gmail_msg">
> Subscribers: llvm-commits<br class="gmail_msg">
><br class="gmail_msg">
> Differential Revision: <a href="https://reviews.llvm.org/D31345" rel="noreferrer" class="gmail_msg" target="_blank">https://reviews.llvm.org/D31345</a><br class="gmail_msg">
><br class="gmail_msg">
> Modified:<br class="gmail_msg">
> compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h<br class="gmail_msg">
> compiler-rt/trunk/lib/xray/xray_flags.inc<br class="gmail_msg">
> compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc<br class="gmail_msg">
><br class="gmail_msg">
> Modified: compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h<br class="gmail_msg">
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h?rev=299629&r1=299628&r2=299629&view=diff" rel="noreferrer" class="gmail_msg" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h?rev=299629&r1=299628&r2=299629&view=diff</a><br class="gmail_msg">
> ==============================================================================<br class="gmail_msg">
> --- compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h (original)<br class="gmail_msg">
> +++ compiler-rt/trunk/lib/xray/xray_fdr_logging_impl.h Thu Apr 6 02:14:43 2017<br class="gmail_msg">
> @@ -32,6 +32,8 @@<br class="gmail_msg">
> #include "xray_buffer_queue.h"<br class="gmail_msg">
> #include "xray_defs.h"<br class="gmail_msg">
> #include "xray_fdr_log_records.h"<br class="gmail_msg">
> +#include "xray_flags.h"<br class="gmail_msg">
> +#include "xray_tsc.h"<br class="gmail_msg">
><br class="gmail_msg">
> namespace __xray {<br class="gmail_msg">
><br class="gmail_msg">
> @@ -108,9 +110,17 @@ static void processFunctionHook(int32_t<br class="gmail_msg">
> //-----------------------------------------------------------------------------|<br class="gmail_msg">
><br class="gmail_msg">
> namespace {<br class="gmail_msg">
> +<br class="gmail_msg">
> thread_local BufferQueue::Buffer Buffer;<br class="gmail_msg">
> thread_local char *RecordPtr = nullptr;<br class="gmail_msg">
><br class="gmail_msg">
> +// The number of FunctionEntry records immediately preceding RecordPtr.<br class="gmail_msg">
> +thread_local uint8_t NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> +<br class="gmail_msg">
> +// The number of adjacent, consecutive pairs of FunctionEntry, Tail Exit<br class="gmail_msg">
> +// records preceding RecordPtr.<br class="gmail_msg">
> +thread_local uint8_t NumTailCalls = 0;<br class="gmail_msg">
> +<br class="gmail_msg">
> constexpr auto MetadataRecSize = sizeof(MetadataRecord);<br class="gmail_msg">
> constexpr auto FunctionRecSize = sizeof(FunctionRecord);<br class="gmail_msg">
><br class="gmail_msg">
> @@ -209,6 +219,8 @@ static inline void writeNewBufferPreambl<br class="gmail_msg">
> }<br class="gmail_msg">
> std::memcpy(MemPtr, Records, sizeof(MetadataRecord) * InitRecordsCount);<br class="gmail_msg">
> MemPtr += sizeof(MetadataRecord) * InitRecordsCount;<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> static inline void setupNewBuffer(const BufferQueue::Buffer &Buffer,<br class="gmail_msg">
> @@ -221,6 +233,8 @@ static inline void setupNewBuffer(const<br class="gmail_msg">
> // This is typically clock_gettime, but callers have injection ability.<br class="gmail_msg">
> wall_clock_reader(CLOCK_MONOTONIC, &TS);<br class="gmail_msg">
> writeNewBufferPreamble(Tid, TS, RecordPtr);<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> static inline void writeNewCPUIdMetadata(uint16_t CPU, uint64_t TSC,<br class="gmail_msg">
> @@ -237,6 +251,8 @@ static inline void writeNewCPUIdMetadata<br class="gmail_msg">
> std::memcpy(&NewCPUId.Data[sizeof(CPU)], &TSC, sizeof(TSC));<br class="gmail_msg">
> std::memcpy(MemPtr, &NewCPUId, sizeof(MetadataRecord));<br class="gmail_msg">
> MemPtr += sizeof(MetadataRecord);<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> static inline void writeNewCPUIdMetadata(uint16_t CPU,<br class="gmail_msg">
> @@ -251,6 +267,8 @@ static inline void writeEOBMetadata(char<br class="gmail_msg">
> // For now we don't write any bytes into the Data field.<br class="gmail_msg">
> std::memcpy(MemPtr, &EOBMeta, sizeof(MetadataRecord));<br class="gmail_msg">
> MemPtr += sizeof(MetadataRecord);<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> static inline void writeEOBMetadata() XRAY_NEVER_INSTRUMENT {<br class="gmail_msg">
> @@ -269,6 +287,8 @@ static inline void writeTSCWrapMetadata(<br class="gmail_msg">
> std::memcpy(&TSCWrap.Data, &TSC, sizeof(TSC));<br class="gmail_msg">
> std::memcpy(MemPtr, &TSCWrap, sizeof(MetadataRecord));<br class="gmail_msg">
> MemPtr += sizeof(MetadataRecord);<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> static inline void writeTSCWrapMetadata(uint64_t TSC) XRAY_NEVER_INSTRUMENT {<br class="gmail_msg">
> @@ -289,13 +309,35 @@ static inline void writeFunctionRecord(i<br class="gmail_msg">
><br class="gmail_msg">
> switch (EntryType) {<br class="gmail_msg">
> case XRayEntryType::ENTRY:<br class="gmail_msg">
> + ++NumConsecutiveFnEnters;<br class="gmail_msg">
> + FuncRecord.RecordKind = uint8_t(FunctionRecord::RecordKinds::FunctionEnter);<br class="gmail_msg">
> + break;<br class="gmail_msg">
> case XRayEntryType::LOG_ARGS_ENTRY:<br class="gmail_msg">
> + // We should not rewind functions with logged args.<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> FuncRecord.RecordKind = uint8_t(FunctionRecord::RecordKinds::FunctionEnter);<br class="gmail_msg">
> break;<br class="gmail_msg">
> case XRayEntryType::EXIT:<br class="gmail_msg">
> + // If we've decided to log the function exit, we will never erase the log<br class="gmail_msg">
> + // before it.<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> FuncRecord.RecordKind = uint8_t(FunctionRecord::RecordKinds::FunctionExit);<br class="gmail_msg">
> break;<br class="gmail_msg">
> case XRayEntryType::TAIL:<br class="gmail_msg">
> + // If we just entered the function we're tail exiting from or erased every<br class="gmail_msg">
> + // invocation since then, this function entry tail pair is a candidate to<br class="gmail_msg">
> + // be erased when the child function exits.<br class="gmail_msg">
> + if (NumConsecutiveFnEnters > 0) {<br class="gmail_msg">
> + ++NumTailCalls;<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + } else {<br class="gmail_msg">
> + // We will never be able to erase this tail call since we have logged<br class="gmail_msg">
> + // something in between the function entry and tail exit.<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> + NumConsecutiveFnEnters = 0;<br class="gmail_msg">
> + }<br class="gmail_msg">
> FuncRecord.RecordKind =<br class="gmail_msg">
> uint8_t(FunctionRecord::RecordKinds::FunctionTailExit);<br class="gmail_msg">
> break;<br class="gmail_msg">
> @@ -337,6 +379,8 @@ static inline void processFunctionHook(<br class="gmail_msg">
> // We assume that we'll support only 65536 CPUs for x86_64.<br class="gmail_msg">
> thread_local uint16_t CurrentCPU = std::numeric_limits<uint16_t>::max();<br class="gmail_msg">
> thread_local uint64_t LastTSC = 0;<br class="gmail_msg">
> + thread_local uint64_t LastFunctionEntryTSC = 0;<br class="gmail_msg">
> + thread_local uint64_t NumberOfTicksThreshold = 0;<br class="gmail_msg">
><br class="gmail_msg">
> // Make sure a thread that's ever called handleArg0 has a thread-local<br class="gmail_msg">
> // live reference to the buffer queue for this particular instance of<br class="gmail_msg">
> @@ -379,6 +423,10 @@ static inline void processFunctionHook(<br class="gmail_msg">
> return;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> + uint64_t CycleFrequency = getTSCFrequency();<br class="gmail_msg">
> + NumberOfTicksThreshold = CycleFrequency *<br class="gmail_msg">
> + flags()->xray_fdr_log_func_duration_threshold_us /<br class="gmail_msg">
> + 1000000;<br class="gmail_msg">
> setupNewBuffer(Buffer, wall_clock_reader);<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> @@ -441,6 +489,10 @@ static inline void processFunctionHook(<br class="gmail_msg">
> BufferQueue::getErrorString(EC));<br class="gmail_msg">
> return;<br class="gmail_msg">
> }<br class="gmail_msg">
> + uint64_t CycleFrequency = getTSCFrequency();<br class="gmail_msg">
> + NumberOfTicksThreshold = CycleFrequency *<br class="gmail_msg">
> + flags()->xray_fdr_log_func_duration_threshold_us /<br class="gmail_msg">
> + 1000000;<br class="gmail_msg">
> setupNewBuffer(Buffer, wall_clock_reader);<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> @@ -486,10 +538,92 @@ static inline void processFunctionHook(<br class="gmail_msg">
> RecordTSCDelta = Delta;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> - // We then update our "LastTSC" and "CurrentCPU" thread-local variables to aid<br class="gmail_msg">
> - // us in future computations of this TSC delta value.<br class="gmail_msg">
> LastTSC = TSC;<br class="gmail_msg">
> CurrentCPU = CPU;<br class="gmail_msg">
> + using AlignedFuncStorage =<br class="gmail_msg">
> + std::aligned_storage<sizeof(FunctionRecord),<br class="gmail_msg">
> + alignof(FunctionRecord)>::type;<br class="gmail_msg">
> + switch (Entry) {<br class="gmail_msg">
> + case XRayEntryType::ENTRY:<br class="gmail_msg">
> + case XRayEntryType::LOG_ARGS_ENTRY:<br class="gmail_msg">
> + // Update the thread local state for the next invocation.<br class="gmail_msg">
> + LastFunctionEntryTSC = TSC;<br class="gmail_msg">
> + break;<br class="gmail_msg">
> + case XRayEntryType::TAIL:<br class="gmail_msg">
> + break;<br class="gmail_msg">
> + case XRayEntryType::EXIT:<br class="gmail_msg">
> + // Break out and write the exit record if we can't erase any functions.<br class="gmail_msg">
> + if (NumConsecutiveFnEnters == 0 ||<br class="gmail_msg">
> + (TSC - LastFunctionEntryTSC) >= NumberOfTicksThreshold)<br class="gmail_msg">
> + break;<br class="gmail_msg">
> + // Otherwise we unwind functions that are too short to log by decrementing<br class="gmail_msg">
> + // our view ptr into the buffer. We can erase a Function Entry record and<br class="gmail_msg">
> + // neglect to log our EXIT. We have to make sure to update some state like<br class="gmail_msg">
> + // the LastTSC and count of consecutive FunctionEntry records.<br class="gmail_msg">
> + RecordPtr -= FunctionRecSize;<br class="gmail_msg">
> + AlignedFuncStorage AlignedFuncRecordBuffer;<br class="gmail_msg">
> + const auto &FuncRecord = *reinterpret_cast<FunctionRecord *>(<br class="gmail_msg">
> + std::memcpy(&AlignedFuncRecordBuffer, RecordPtr, FunctionRecSize));<br class="gmail_msg">
> + assert(FuncRecord.RecordKind ==<br class="gmail_msg">
> + uint8_t(FunctionRecord::RecordKinds::FunctionEnter) &&<br class="gmail_msg">
> + "Expected to find function entry recording when rewinding.");<br class="gmail_msg">
> + assert(FuncRecord.FuncId == (FuncId & ~(0x0F << 28)) &&<br class="gmail_msg">
> + "Expected matching function id when rewinding Exit");<br class="gmail_msg">
> + --NumConsecutiveFnEnters;<br class="gmail_msg">
> + LastTSC -= FuncRecord.TSCDelta;<br class="gmail_msg">
> +<br class="gmail_msg">
> + // We unwound one call. Update the state and return without writing a log.<br class="gmail_msg">
> + if (NumConsecutiveFnEnters != 0) {<br class="gmail_msg">
> + LastFunctionEntryTSC = LastFunctionEntryTSC - FuncRecord.TSCDelta;<br class="gmail_msg">
> + return;<br class="gmail_msg">
> + }<br class="gmail_msg">
> +<br class="gmail_msg">
> + // Otherwise we've rewound the stack of all function entries, we might be<br class="gmail_msg">
> + // able to rewind further by erasing tail call functions that are being<br class="gmail_msg">
> + // exited from via this exit.<br class="gmail_msg">
> + LastFunctionEntryTSC = 0;<br class="gmail_msg">
> + auto RewindingTSC = LastTSC;<br class="gmail_msg">
> + auto RewindingRecordPtr = RecordPtr - FunctionRecSize;<br class="gmail_msg">
> + while (NumTailCalls > 0) {<br class="gmail_msg">
> + AlignedFuncStorage TailExitRecordBuffer;<br class="gmail_msg">
> + // Rewind the TSC back over the TAIL EXIT record.<br class="gmail_msg">
> + const auto &ExpectedTailExit =<br class="gmail_msg">
> + *reinterpret_cast<FunctionRecord *>(std::memcpy(<br class="gmail_msg">
> + &TailExitRecordBuffer, RewindingRecordPtr, FunctionRecSize));<br class="gmail_msg">
> +<br class="gmail_msg">
> + assert(ExpectedTailExit.RecordKind ==<br class="gmail_msg">
> + uint8_t(FunctionRecord::RecordKinds::FunctionTailExit) &&<br class="gmail_msg">
> + "Expected to find tail exit when rewinding.");<br class="gmail_msg">
> + auto TailExitFuncId = ExpectedTailExit.FuncId;<br class="gmail_msg">
> + RewindingRecordPtr -= FunctionRecSize;<br class="gmail_msg">
> + RewindingTSC -= ExpectedTailExit.TSCDelta;<br class="gmail_msg">
> + AlignedFuncStorage FunctionEntryBuffer;<br class="gmail_msg">
> + const auto &ExpectedFunctionEntry =<br class="gmail_msg">
> + *reinterpret_cast<FunctionRecord *>(std::memcpy(<br class="gmail_msg">
> + &FunctionEntryBuffer, RewindingRecordPtr, FunctionRecSize));<br class="gmail_msg">
> + assert(ExpectedFunctionEntry.RecordKind ==<br class="gmail_msg">
> + uint8_t(FunctionRecord::RecordKinds::FunctionEnter) &&<br class="gmail_msg">
> + "Expected to find function entry when rewinding tail call.");<br class="gmail_msg">
> + assert(ExpectedFunctionEntry.FuncId == TailExitFuncId &&<br class="gmail_msg">
> + "Expected funcids to match when rewinding tail call.");<br class="gmail_msg">
> +<br class="gmail_msg">
> + if ((TSC - RewindingTSC) < NumberOfTicksThreshold) {<br class="gmail_msg">
> + // We can erase a tail exit pair that we're exiting through since<br class="gmail_msg">
> + // its duration is under threshold.<br class="gmail_msg">
> + --NumTailCalls;<br class="gmail_msg">
> + RewindingRecordPtr -= FunctionRecSize;<br class="gmail_msg">
> + RewindingTSC -= ExpectedFunctionEntry.TSCDelta;<br class="gmail_msg">
> + RecordPtr -= 2 * FunctionRecSize;<br class="gmail_msg">
> + LastTSC = RewindingTSC;<br class="gmail_msg">
> + } else {<br class="gmail_msg">
> + // This tail call exceeded the threshold duration. It will not<br class="gmail_msg">
> + // be erased.<br class="gmail_msg">
> + NumTailCalls = 0;<br class="gmail_msg">
> + return;<br class="gmail_msg">
> + }<br class="gmail_msg">
> + }<br class="gmail_msg">
> + return; // without writing log.<br class="gmail_msg">
> + }<br class="gmail_msg">
><br class="gmail_msg">
> writeFunctionRecord(FuncId, RecordTSCDelta, Entry, RecordPtr);<br class="gmail_msg">
><br class="gmail_msg">
> @@ -510,5 +644,4 @@ static inline void processFunctionHook(<br class="gmail_msg">
> } // namespace __xray_fdr_internal<br class="gmail_msg">
><br class="gmail_msg">
> } // namespace __xray<br class="gmail_msg">
> -<br class="gmail_msg">
> #endif // XRAY_XRAY_FDR_LOGGING_IMPL_H<br class="gmail_msg">
><br class="gmail_msg">
> Modified: compiler-rt/trunk/lib/xray/xray_flags.inc<br class="gmail_msg">
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_flags.inc?rev=299629&r1=299628&r2=299629&view=diff" rel="noreferrer" class="gmail_msg" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_flags.inc?rev=299629&r1=299628&r2=299629&view=diff</a><br class="gmail_msg">
> ==============================================================================<br class="gmail_msg">
> --- compiler-rt/trunk/lib/xray/xray_flags.inc (original)<br class="gmail_msg">
> +++ compiler-rt/trunk/lib/xray/xray_flags.inc Thu Apr 6 02:14:43 2017<br class="gmail_msg">
> @@ -22,3 +22,6 @@ XRAY_FLAG(const char *, xray_logfile_bas<br class="gmail_msg">
> "Filename base for the xray logfile.")<br class="gmail_msg">
> XRAY_FLAG(bool, xray_fdr_log, false,<br class="gmail_msg">
> "Whether to install the flight data recorder logging implementation.")<br class="gmail_msg">
> +XRAY_FLAG(int, xray_fdr_log_func_duration_threshold_us, 5,<br class="gmail_msg">
> + "FDR logging will try to skip functions that execute for fewer "<br class="gmail_msg">
> + "microseconds than this threshold.")<br class="gmail_msg">
><br class="gmail_msg">
> Modified: compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc<br class="gmail_msg">
> URL: <a href="http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc?rev=299629&r1=299628&r2=299629&view=diff" rel="noreferrer" class="gmail_msg" target="_blank">http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc?rev=299629&r1=299628&r2=299629&view=diff</a><br class="gmail_msg">
> ==============================================================================<br class="gmail_msg">
> --- compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc (original)<br class="gmail_msg">
> +++ compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc Thu Apr 6 02:14:43 2017<br class="gmail_msg">
> @@ -1,7 +1,10 @@<br class="gmail_msg">
> // RUN: %clangxx_xray -g -std=c++11 %s -o %t<br class="gmail_msg">
> -// RUN: XRAY_OPTIONS="patch_premain=false xray_naive_log=false xray_logfile_base=fdr-logging-test- xray_fdr_log=true verbosity=1" %run %t 2>&1 | FileCheck %s<br class="gmail_msg">
> -// RUN: %llvm_xray convert --symbolize --output-format=yaml -instr_map=%t "`ls fdr-logging-test-* | head -1`" | FileCheck %s --check-prefix TRACE<br class="gmail_msg">
> +// RUN: XRAY_OPTIONS="patch_premain=false xray_naive_log=false xray_logfile_base=fdr-logging-test- xray_fdr_log=true verbosity=1 xray_fdr_log_func_duration_threshold_us=0" %run %t 2>&1 | FileCheck %s<br class="gmail_msg">
> +// RUN: XRAY_OPTIONS="patch_premain=false xray_naive_log=false xray_logfile_base=fdr-unwrite-test- xray_fdr_log=true verbosity=1 xray_fdr_log_func_duration_threshold_us=5000" %run %t 2>&1 | FileCheck %s<br class="gmail_msg">
> +// RUN: %llvm_xray convert --symbolize --output-format=yaml -instr_map=%t "`ls fdr-logging-test-* | head -1`" | FileCheck %s --check-prefix=TRACE<br class="gmail_msg">
> +// RUN: %llvm_xray convert --symbolize --output-format=yaml -instr_map=%t "`ls fdr-unwrite-test-* | head -1`" | FileCheck %s --check-prefix=UNWRITE<br class="gmail_msg">
> // RUN: rm fdr-logging-test-*<br class="gmail_msg">
> +// RUN: rm fdr-unwrite-test-*<br class="gmail_msg">
> // FIXME: Make llvm-xray work on non-x86_64 as well.<br class="gmail_msg">
> // REQUIRES: x86_64-linux<br class="gmail_msg">
><br class="gmail_msg">
> @@ -61,8 +64,6 @@ int main(int argc, char *argv[]) {<br class="gmail_msg">
> return 0;<br class="gmail_msg">
> }<br class="gmail_msg">
><br class="gmail_msg">
> -<br class="gmail_msg">
> -<br class="gmail_msg">
> // Check that we're able to see two threads, each entering and exiting fA().<br class="gmail_msg">
> // TRACE-DAG: - { type: 0, func-id: [[FIDA:[0-9]+]], function: {{.*fA.*}}, cpu: {{.*}}, thread: [[THREAD1:[0-9]+]], kind: function-enter, tsc: {{[0-9]+}} }<br class="gmail_msg">
> // TRACE: - { type: 0, func-id: [[FIDA]], function: {{.*fA.*}}, cpu: {{.*}}, thread: [[THREAD1]], kind: function-exit, tsc: {{[0-9]+}} }<br class="gmail_msg">
> @@ -80,3 +81,9 @@ int main(int argc, char *argv[]) {<br class="gmail_msg">
> // TRACE: - { type: 0, func-id: [[FIDB]], function: {{.*fB.*}}, cpu: {{.*}}, thread: [[THREAD1]], kind: function-exit, tsc: {{[0-9]+}} }<br class="gmail_msg">
> // TRACE-DAG: - { type: 0, func-id: [[FIDB]], function: {{.*fB.*}}, cpu: {{.*}}, thread: [[THREAD2:[0-9]+]], kind: function-enter, tsc: {{[0-9]+}} }<br class="gmail_msg">
> // TRACE: - { type: 0, func-id: [[FIDB]], function: {{.*fB.*}}, cpu: {{.*}}, thread: [[THREAD2]], kind: function-exit, tsc: {{[0-9]+}} }<br class="gmail_msg">
> +<br class="gmail_msg">
> +// Assert that when unwriting is enabled with a high threshold time, all the function records are erased. A CPU switch could erroneously fail this test, but<br class="gmail_msg">
> +// is unlikely given the test program.<br class="gmail_msg">
> +// UNWRITE: header<br class="gmail_msg">
> +// UNWRITE-NOT: function-enter<br class="gmail_msg">
> +// UNWRITE-NOT: function-exit<br class="gmail_msg">
><br class="gmail_msg">
><br class="gmail_msg">
> _______________________________________________<br class="gmail_msg">
> llvm-commits mailing list<br class="gmail_msg">
> <a href="mailto:llvm-commits@lists.llvm.org" class="gmail_msg" target="_blank">llvm-commits@lists.llvm.org</a><br class="gmail_msg">
> <a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits" rel="noreferrer" class="gmail_msg" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits</a><br class="gmail_msg">
><br class="gmail_msg">
<br class="gmail_msg">
<br class="gmail_msg">
--<br class="gmail_msg">
<br class="gmail_msg">
-Bill Seurer<br class="gmail_msg">
<br class="gmail_msg">
</blockquote></div>