One of the threads in Plasmashell hogs one system CPU 100%. I'm guessing it's looping inside some QString method. I'll report this bug to Qt as well. I do not know how to reproduce this bug. It's kinda there without me knowing. Looking at the stack trace, it seems to be the similar bug to 366319, which I reported a time ago. Reproducible: Sometimes Id Target Id Frame 40 Thread 0x7fe6ea01a900 (LWP 15037) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 39 Thread 0x7fe4257fa700 (LWP 31430) pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:225 38 Thread 0x7fe459d7f700 (LWP 29727) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 37 Thread 0x7fe45aba5700 (LWP 29723) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 36 Thread 0x7fe462515700 (LWP 29721) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 35 Thread 0x7fe4635ef700 (LWP 29714) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 34 Thread 0x7fe45bfff700 (LWP 29557) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 33 Thread 0x7fe46e594700 (LWP 29555) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 32 Thread 0x7fe46f7b5700 (LWP 16823) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 31 Thread 0x7fe4789b0700 (LWP 16821) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 30 Thread 0x7fe47a585700 (LWP 16784) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 29 Thread 0x7fe5d23e2700 (LWP 16783) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 28 Thread 0x7fe5d190b700 (LWP 16742) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 27 Thread 0x7fe5d37fe700 (LWP 16361) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 26 Thread 0x7fe5d3fff700 (LWP 16360) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 25 Thread 0x7fe5f0ff9700 (LWP 16359) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 24 Thread 0x7fe5f17fa700 (LWP 16358) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 23 Thread 0x7fe5f1ffb700 (LWP 16357) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 22 Thread 0x7fe5f27fc700 (LWP 16356) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 21 Thread 0x7fe5f2ffd700 (LWP 16355) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 20 Thread 0x7fe5f37fe700 (LWP 16354) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 19 Thread 0x7fe5f3fff700 (LWP 16353) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 18 Thread 0x7fe6109e8700 (LWP 16352) 0x00007fe61cc0a594 in QConcatenable<QByteArray>::appendTo (out=<synthetic pointer>, ba=<synthetic pointer>) at /usr/include/qt5/QtCore/qstringbuilder.h:348 17 Thread 0x7fe6111e9700 (LWP 16351) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 16 Thread 0x7fe6119ea700 (LWP 16350) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 15 Thread 0x7fe6121eb700 (LWP 16349) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 14 Thread 0x7fe6129ec700 (LWP 16348) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 13 Thread 0x7fe6131ed700 (LWP 16347) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 12 Thread 0x7fe6139ee700 (LWP 16346) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 11 Thread 0x7fe61fdf5700 (LWP 16337) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 10 Thread 0x7fe61f182700 (LWP 16255) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 9 Thread 0x7fe6260bd700 (LWP 15690) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 8 Thread 0x7fe6269fe700 (LWP 15688) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 7 Thread 0x7fe634afe700 (LWP 15687) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 6 Thread 0x7fe64224e700 (LWP 15674) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 5 Thread 0x7fe6cd379700 (LWP 15596) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 4 Thread 0x7fe6cf279700 (LWP 15595) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 3 Thread 0x7fe6dcd19700 (LWP 15161) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 2 Thread 0x7fe6de556700 (LWP 15057) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 * 1 Thread 0x7fe6dfd96700 (LWP 15056) 0x00007fe6f750cb1d in poll () at ../sysdeps/unix/syscall-template.S:84 [Switching to thread 18 (Thread 0x7fe6109e8700 (LWP 16352))] #0 0x00007fe61cc0a594 in QConcatenable<QByteArray>::appendTo (out=<synthetic pointer>, ba=<synthetic pointer>) at /usr/include/qt5/QtCore/qstringbuilder.h:348 348 *out++ = *a++; #0 0x00007fe61cc0a594 in QConcatenable<QByteArray>::appendTo (out=<synthetic pointer>, ba=<synthetic pointer>) at /usr/include/qt5/QtCore/qstringbuilder.h:348 a = 0x7fe435c24b68 "ate.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/updat"... #1 QConcatenable<QStringBuilder<QStringBuilder<QByteArray, char>, QByteArray> >::appendTo<char> (out=<synthetic pointer>, p=...) at /usr/include/qt5/QtCore/qstringbuilder.h:366 No locals. #2 QStringBuilder<QStringBuilder<QByteArray, char>, QByteArray>::convertTo<QByteArray> ( this=<optimized out>) at /usr/include/qt5/QtCore/qstringbuilder.h:112 len = 61115777 d = 0x7fe5e71091c3 "ate.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/updat"... start = 0x7fe5e40ef678 "update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/update.mar/libnss3.so/up"... #3 QStringBuilder<QStringBuilder<QByteArray, char>, QByteArray>::operator QByteArray ( this=<optimized out>) at /usr/include/qt5/QtCore/qstringbuilder.h:125 No locals. #4 Baloo::DocumentUrlDB::get (this=this@entry=0x7fe6109e77f0, docId=docId@entry=69245743373810944) at /usr/src/debug/baloo-5.24.0/src/engine/documenturldb.cpp:155 p = {parentId = 69245331056950528, name = {d = 0x7fe5e40013d0}} idFilenameDb = {m_txn = 0x7fe5e40eb7c0, m_dbi = 8} path = {parentId = 69245700424137984, name = {d = 0x7fe5e40108c0}} ret = {d = 0x7fe432c0b010} id = <optimized out> #5 0x00007fe61cc24ff1 in Baloo::Transaction::documentUrl (this=this@entry=0x7fe6109e78a0, id=69245743373810944) at /usr/src/debug/baloo-5.24.0/src/engine/transaction.cpp:104 docUrlDb = {m_txn = 0x7fe5e40eb7c0, m_idFilenameDbi = 8, m_idTreeDbi = 7} #6 0x00007fe61d081173 in Baloo::SearchStore::exec (this=this@entry=0x7fe6109e7990, term=..., offset=<optimized out>, limit=<optimized out>, sortResults=<optimized out>) at /usr/src/debug/baloo-5.24.0/src/lib/searchstore.cpp:107 id = <optimized out> filePath = {static null = {<No data fields>}, d = 0x7fe5e402b6d8} i = 0 resultIds = {d = 0x7fe5e4005920} compFunc = {__tr = @0x7fe6109e78a0} results = {<QList<QString>> = {<QListSpecialMethods<QString>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = { _q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fe6f8370120 <QListData::shared_null>}, d = 0x7fe6f8370120 <QListData::shared_null>}}, <No data fields>} tr = {m_dbis = @0x7fe61ce39030, m_txn = 0x7fe5e40eb7c0, m_env = 0x7fe5f8003730, m_writeTrans = 0x0} it = {d = 0x7fe5e4011c90} #7 0x00007fe61d06f40f in Baloo::Query::exec (this=this@entry=0x7fe6109e7a50) at /usr/src/debug/baloo-5.24.0/src/lib/query.cpp:210 term = {d = 0x7fe5e40051b0} searchStore = { m_db = 0x7fe61ce39020 <(anonymous namespace)::Q_QGS_s_db::innerFunction()::holder>, m_prefixes = {{d = 0x7fe5e40eb750, e = 0x7fe5e40eb750}}} result = {<QList<QString>> = {<QListSpecialMethods<QString>> = {<No data fields>}, { p = {static shared_null = {ref = {atomic = { _q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fe5e4005560}, d = 0x7fe5e4005560}}, <No data fields>} #8 0x00007fe61d2c37e0 in SearchRunner::match (this=this@entry=0x564fdcf31b90, context=..., type=..., category=...) at /usr/src/debug/plasma-workspace-5.7.3/runners/baloo/baloosearchrunner.cpp:99 categories = {<QList<QString>> = {<QListSpecialMethods<QString>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = { static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x564fdcf34b60}, d = 0x564fdcf34b60}}, <No data fields>} query = {d = 0x7fe5e40ec020} it = {d = 0x7fe6f8370120 <QListData::shared_null>} matches = {<QListSpecialMethods<Plasma::QueryMatch>> = {<No data fields>}, {p = { static shared_null = {ref = {atomic = { _q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fe6f8370120 <QListData::shared_null>}, d = 0x7fe6f8370120 <QListData::shared_null>}} mimeDb = {d = 0x7fe5e402b610} relevance = <optimized out> #9 0x00007fe61d2c47f9 in SearchRunner::match (this=0x564fdcf31b90, context=...) at /usr/src/debug/plasma-workspace-5.7.3/runners/baloo/baloosearchrunner.cpp:168 text = {static null = {<No data fields>}, d = 0x564fde205940} matches = {<QListSpecialMethods<Plasma::QueryMatch>> = {<No data fields>}, {p = { static shared_null = {ref = {atomic = { _q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fe5e402b680}, d = 0x7fe5e402b680}} #10 0x00007fe638542068 in Plasma::AbstractRunner::performMatch (this=0x564fdcf31b90, localContext=...) at /usr/src/debug/krunner-5.24.0/src/abstractrunner.cpp:131 time = {mds = 38916068} runtime = <optimized out> slowed = <optimized out> #11 0x00007fe637ca0427 in ThreadWeaver::Executor::run (this=<optimized out>, job=..., thread=<optimized out>) at /usr/src/debug/threadweaver-5.24.0/src/executor.cpp:52 No locals. #12 0x00007fe637c9f060 in ThreadWeaver::Job::execute (this=<optimized out>, self=..., th=0x564fdcee3cc0) at /usr/src/debug/threadweaver-5.24.0/src/job.cpp:83 No locals. #13 0x00007fe637c9e7c0 in ThreadWeaver::Thread::run (this=0x564fdcee3cc0) at /usr/src/debug/threadweaver-5.24.0/src/thread.cpp:114 wasBusy = true #14 0x00007fe6f811700c in QThreadPrivate::start (arg=0x564fdcee3cc0) at thread/qthread_unix.cpp:341 __clframe = {__cancel_routine = 0x7fe6f81161c0 <QThreadPrivate::finish(void*)>, __cancel_arg = 0x564fdcee3cc0, __do_it = 1, __cancel_type = <optimized out>} thr = 0x564fdcee3cc0 data = 0x564fdcef2f50 #15 0x00007fe6f686a61a in start_thread (arg=0x7fe6109e8700) at pthread_create.c:334 __res = <optimized out> pd = 0x7fe6109e8700 now = <optimized out> unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140626098030336, 826749333446829647, 140736515912639, 140626098030336, 8388608, 0, -813720932489910705, -813786840084928945}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}} not_first_call = <optimized out> pagesize_m1 = <optimized out> sp = <optimized out> freesize = <optimized out> #16 0x00007fe6f751859d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 No locals. quit
#7 0x00007fe61d06f40f in Baloo::Query::exec (this=this@entry=0x7fe6109e7a50)
*** This bug has been marked as a duplicate of bug 354705 ***