Details
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Bug
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Resolution: Unresolved
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P2: Important
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5.15.11
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Embedded Linux
Ubuntu 22.04
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Linux/Wayland,
Description
Valgrind memcheck shows not one-time, but repeated "definitely lost" memory leaks in QML Loader:
1. Image with ShaderEffect applied:
shader_leak_test.zip
- sample app src, reloads Image with ShaderEffect each 100ms
shader_memcheck_01_definite_only_38_iter.log- valgrind output
shader_memcheck_02_definite_only_78_iter.xml- valgrind output for convenient import in QtCreator
==460027== 1,904 bytes in 34 blocks are definitely lost in loss record 53,819 of 54,478 ==460027== at 0x4849013: operator new(unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==460027== by 0x11BEC702: QQuickOpenGLShaderEffectCommon::lookThroughShaderCode(QQuickItem*, QMetaObject const*, QQuickOpenGLShaderEffectMaterialKey::ShaderType, QByteArray const&) (qquickopenglshadereffect.cpp:371) ... ==460027== LEAK SUMMARY: ==460027== definitely lost: 2,184 bytes in 45 blocks
2. Colored Rectangle
item_leak_test.zip- sample app src, reloads Rectangle each 50ms
valgrind output
item_memcheck_07_rect_200ms_1000_reloads.log
item_memcheck_09_rect_50ms_500_trim_clear_no_result.log
==492485== 3,944 bytes in 493 blocks are definitely lost in loss record 20,699 of 21,013 ==492485== at 0x484A2F3: operator new[](unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==492485== by 0x55CF8CA: QQmlContextData::initFromTypeCompilationUnit(QQmlRefPointer<QV4::ExecutableCompilationUnit> const&, int) (qqmlcontext.cpp:872) ... ==492485== LEAK SUMMARY: ==492485== definitely lost: 4,032 bytes in 504 blocks
NOTE: Calling trimComponentCache() and clearComponentCache() in sample #2 has no effect.
Defect is similar to QTBUG-61536
Our product Qt app has way more complex app scene and above leaks lead to a memory shortage in the system under a long run and rapid QML view switching by user.
Below are examples of valgrind output for our product Qt app ran on the Linux desktop for a couple of minutes under the stress test for Loader:
1. QQuickOpenGLShaderEffectCommon::lookThroughShaderCode()
==376054== 22,848 bytes in 408 blocks are definitely lost in loss record 102,877 of 103,679 ==376054== at 0x4849013: operator new(unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==376054== by 0x5356702: QQuickOpenGLShaderEffectCommon::lookThroughShaderCode(QQuickItem*, QMetaObject const*, QQuickOpenGLShaderEffectMaterialKey::ShaderType, QByteArray const&) (qquickopenglshadereffect.cpp:371) ...
2. QQmlContextData::initFromTypeCompilationUnit()
==376054== 3,776 bytes in 472 blocks are definitely lost in loss record 99,847 of 103,679 ==376054== at 0x484A2F3: operator new[](unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==376054== by 0x6BCF8CA: QQmlContextData::initFromTypeCompilationUnit(QQmlRefPointer<QV4::ExecutableCompilationUnit> const&, int) (qqmlcontext.cpp:872) ...
3. QQmlPropertyCache::copyAndReserve()
==376054== 344 bytes in 43 blocks are definitely lost in loss record 82,018 of 103,679 ==376054== at 0x484A2F3: operator new[](unsigned long) (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==376054== by 0x6C047D7: QLinkedStringHash<QPair<int, QQmlPropertyData*> >::linkAndReserve(QLinkedStringHash<QPair<int, QQmlPropertyData*> > const&, int) (qlinkedstringhash_p.h:82) ==376054== by 0x6BFF875: copy (qqmlpropertycache.cpp:265) ==376054== by 0x6BFF875: QQmlPropertyCache::copyAndReserve(int, int, int, int) (qqmlpropertycache.cpp:281) ...
Attachments
Gerrit Reviews
| For Gerrit Dashboard: QTBUG-119301 | ||||||
|---|---|---|---|---|---|---|
| # | Subject | Branch | Project | Status | CR | V |
| 533938,2 | rhi: gl: Empty the program binary cache upon release(Cached)Resources | dev | qt/qtbase | Status: NEW | 0 | 0 |