Comments (4)
milianw
commented on September 26, 2024
1
It's not searching for . - it was searching for a file with an empty name.
from hotspot.
GitMensch
commented on September 26, 2024
Good, that you've found this. Should we move the following to a separate issue?
Furthermore, testing hints at that with each output of
PerfUnwind::MissingElfFile: Could not find ELF file for 64/ld-2.17.so. This can break stack unwinding and lead to missing symbols.
we see, the perfparser binary takes longer. I guess perfparerser caches registered elf files (return of
PerfSymbolTable::registerElf()), but only those that can be resolved. In this case it would be good to also cache "invalid" / empty returns; allowing to also decrease the wait time for perf recordings with missing elf files in general and for this repo in the specific tests - see 69ad59b#r1382617529.
from hotspot.
milianw
commented on September 26, 2024
No, as I don't see this as an issue? you only guess without showing any proof
from hotspot.
GitMensch
commented on September 26, 2024
You're reight about the missing proof. Rechecked with current hotspot-perfparser alone - and could not reproduce it.
Without that:
perf stat /tmp/squashfs-root/usr/bin/hotspot-perfparser --input perf.data.true.v2 --output=/dev/null --app /bin #--extra ./lib64/
unhandled feature PerfHeader::CACHE 888
feature not properly read PerfHeader::CPU_TOPOLOGY 228 212
FINISHED_ROUND detected. Switching to automatic buffering
PerfUnwind::MissingElfFile: Could not find ELF file for 64/ld-2.17.so. This can break stack unwinding and lead to missing symbols.
PerfUnwind::MissingElfFile: Could not find ELF file for 64/ld-2.17.so. This can break stack unwinding and lead to missing symbols.
PerfUnwind::MissingElfFile: Could not find ELF file for 64/libc-2.17.so. This can break stack unwinding and lead to missing symbols.
PerfUnwind::MissingElfFile: Could not find ELF file for 64/libc-2.17.so. This can break stack unwinding and lead to missing symbols.
PerfUnwind::MissingElfFile: Could not find ELF file for 64/libc-2.17.so. This can break stack unwinding and lead to missing symbols.
Performance counter stats for '/tmp/squashfs-root/usr/bin/hotspot-perfparser --input perf.data.true.v2 --output=/dev/null --app /bin':
4.90 msec task-clock:u # 0.945 CPUs utilized
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
488 page-faults:u # 99.576 K/sec
11031879 cycles:u # 2.251 GHz
527937 stalled-cycles-frontend:u # 4.79% frontend cycles idle
2621572 stalled-cycles-backend:u # 23.76% backend cycles idle
15618606 instructions:u # 1.42 insn per cycle
# 0.17 stalled cycles per insn
3389329 branches:u # 691.587 M/sec
60722 branch-misses:u # 1.79% of all branches
0.005186040 seconds time elapsed
0.005265000 seconds user
0.000000000 seconds sys
With the additional extra paths the warning message vanishes, but the instructions and computing time increases.
perf stat /tmp/squashfs-root/usr/bin/hotspot-perfparser --input perf.data.true.v2 --output=/dev/null --app /bin --extra ./lib64/
feature not properly read PerfHeader::CPU_TOPOLOGY 228 212
unhandled feature PerfHeader::CACHE 888
FINISHED_ROUND detected. Switching to automatic buffering
Performance counter stats for '/tmp/squashfs-root/usr/bin/hotspot-perfparser --input perf.data.true.v2 --output=/dev/null --app /bin --extra ./lib64/':
5.73 msec task-clock:u # 0.942 CPUs utilized
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
555 page-faults:u # 96.908 K/sec
14401613 cycles:u # 2.515 GHz
667260 stalled-cycles-frontend:u # 4.63% frontend cycles idle
3414886 stalled-cycles-backend:u # 23.71% backend cycles idle
21621729 instructions:u # 1.50 insn per cycle
# 0.16 stalled cycles per insn
4615838 branches:u # 805.964 M/sec
75026 branch-misses:u # 1.63% of all branches
0.006081037 seconds time elapsed
0.006199000 seconds user
0.000000000 seconds sys
Therefore, caching the "empty" seems to primarily drop the amount of warnings from 2 + 3 to 1 + 1.
This may still be useful, but possibly not worth the effort, at least if - as I guess this is a question of adjusting multiple callers.
... but I can check that with the debugger, so:
This message comes from findFile which is commonly called 2+ times for the same entry, no matter if its found or not. Caching the result seems useful (and would then also raise the messages only once):
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="/true", fileName="true", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="/true", fileName="true", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="64/ld-2.17.so", fileName="ld-2.17.so", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
PerfUnwind::MissingElfFile: Could not find ELF file for 64/ld-2.17.so. This can break stack unwinding and lead to missing symbols.
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="64/ld-2.17.so", fileName="ld-2.17.so", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
PerfUnwind::MissingElfFile: Could not find ELF file for 64/ld-2.17.so. This can break stack unwinding and lead to missing symbols.
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="64/libc-2.17.so", fileName="libc-2.17.so", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
PerfUnwind::MissingElfFile: Could not find ELF file for 64/libc-2.17.so. This can break stack unwinding and lead to missing symbols.
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="64/libc-2.17.so", fileName="libc-2.17.so", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
PerfUnwind::MissingElfFile: Could not find ELF file for 64/libc-2.17.so. This can break stack unwinding and lead to missing symbols.
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="64/libc-2.17.so", fileName="libc-2.17.so", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000439aae in PerfSymbolTable::registerElf (this=0x4d7d30, mmap=..., buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:209
#2 0x0000000000420d66 in PerfUnwind::forwardMmapBuffer (this=0x7fffffffd4d0, mmapIt=..., mmapEnd=..., timestamp=43325196779752733) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1008
#3 0x0000000000425f6b in PerfUnwind::flushEventBuffer (this=0x7fffffffd4d0, desiredBufferSize=9772) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfunwind.cpp:1113
PerfUnwind::MissingElfFile: Could not find ELF file for 64/libc-2.17.so. This can break stack unwinding and lead to missing symbols.
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="66dccb7324bc63b326940668f597b476868c0a.debug", fileName="66dccb7324bc63b326940668f597b476868c0a.debug", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000438a03 in PerfSymbolTable::findDebugInfo (this=0x4d7d30, module=<optimized out>, moduleName=<optimized out>, base=4194304, file=0x4f1ee0 "/bin/true", debugLink=<optimized out>, crc=1976527923, debugInfoFilename=0x4fdaf8) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:472
#2 0x000000000040df2f in ?? ()
#3 0x000000000045790c in ?? ()
#0 PerfSymbolTable::findFile (this=0x4d7d30, path="66dccb7324bc63b326940668f597b476868c0a.debug", fileName="66dccb7324bc63b326940668f597b476868c0a.debug", buildId=<QArrayData::shared_null+24> "") at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:162
#1 0x0000000000438a03 in PerfSymbolTable::findDebugInfo (this=0x4d7d30, module=<optimized out>, moduleName=<optimized out>, base=4194304, file=0x4f1ee0 "/bin/true", debugLink=<optimized out>, crc=1976527923, debugInfoFilename=0x4fdaf8) at /__w/hotspot/hotspot/3rdparty/perfparser/app/perfsymboltable.cpp:472
#2 0x000000000040df2f in ?? ()
#3 0x0000000000457e69 in ?? ()
... but again I have no idea where to cache the result.
from hotspot.
Related Issues (20)
- Should we request `--visualize-jumps` even if it is disabled in the settings? HOT 1
- `canVisualizeJumps()` should cache the result HOT 2
- disable "Dissasembly" function for inlined functions (size calculation of inline functions not possible) HOT 13
- clangd warnings (parsers/perf/perfparser.cpp) HOT 1
- SIGSEGV for disasembly when switched HOT 2
- appimage: package QT platforms HOT 1
- BranchDelegate::paint() raises `unexpected jump visualization char: +` HOT 3
- allow to specify objdump + perf on command line HOT 5
- Summary Tab: Top Hotspots per File should not have "filter out/in by symbol"
- perfparser: add elfutlis version info to `--version` (and its debug symbols in the debuginfo appimage package) HOT 2
- Disassembly view: Disassembly broken after 201 HOT 1
- appimage: also package QT debuginfo (or make it otherwise available) HOT 1
- Fails to build with kddockwidgets-2.0.0: error: no viable conversion from 'const QVector<KDDockWidgets::Core::DockWidget *>' to 'const QVector<KDDockWidgets::DockWidgetBase *>' HOT 1
- [com.kdab.kddockwidgets] [error] Couldn't find dock widget frequency
- Too fast clicking at stop, cause segfault
- Disassembly displays old source (caching issue?) and search is broken HOT 8
- chrash in hotspot in handling perfparser output HOT 7
- copyright year needs an adjustment HOT 4
- hotspot in Arch linux AUR not work for a long time, thanks. HOT 3
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from hotspot.