Re: [Interest] Default stack size of QThread
Thanks for your feedback. The latter statement is correct as we are trying to solve the problem due to lack of understanding. Best Regards, Ramakanth On Wed, 30 Aug, 2023, 01:25 Thiago Macieira, wrote: > On Monday, 28 August 2023 23:34:26 PDT Ramakanth Kesireddy wrote: > > Thanks for your feedback. > > As we donot set any stack size for QThread and it looks like it runs out > of > > default stack size limit during long running operation. Hence would like > to > > measure the cumulative stack variables used in a thread so as to set > stack > > size of QThread accordingly. > > That's not how stacks work: long-running has nothing to do with the size > of > the stack. What matters for stack depth is just that: how deeply do you > recurse. > > So I repeat the question: why do you think you need to change anything? Do > you > have a concrete problem? > > Because if you don't, it looks like you're trying to solve a problem that > doesn't exist out of a misunderstanding of how things work. > > -- > Thiago Macieira - thiago.macieira (AT) intel.com > Cloud Software Architect - Intel DCAI Cloud Engineering > ___ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest > ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Default stack size of QThread
On Monday, 28 August 2023 23:34:26 PDT Ramakanth Kesireddy wrote: > Thanks for your feedback. > As we donot set any stack size for QThread and it looks like it runs out of > default stack size limit during long running operation. Hence would like to > measure the cumulative stack variables used in a thread so as to set stack > size of QThread accordingly. That's not how stacks work: long-running has nothing to do with the size of the stack. What matters for stack depth is just that: how deeply do you recurse. So I repeat the question: why do you think you need to change anything? Do you have a concrete problem? Because if you don't, it looks like you're trying to solve a problem that doesn't exist out of a misunderstanding of how things work. -- Thiago Macieira - thiago.macieira (AT) intel.com Cloud Software Architect - Intel DCAI Cloud Engineering smime.p7s Description: S/MIME cryptographic signature ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Default stack size of QThread
As we donot set any stack size for QThread and it looks like it runs out of default stack size limit during long running operation. Hence would like to measure the cumulative stack variables used in a thread so as to set stack size of QThread accordingly. It is possible to measure stack usage, but there is no fun in it. If you're willing to use private QtQml API you can call stackProperties() as declared in [1] to find an approximation of the stack boundaries. You can then compare that with currentStackPointer(), conveniently defined in the same file, to get your stack usage. Mind that it's not really exact. See [2] for the implementation. [1] https://code.qt.io/cgit/qt/qtdeclarative.git/tree/src/qml/memory/qv4stacklimits_p.h [2] https://code.qt.io/cgit/qt/qtdeclarative.git/tree/src/qml/memory/qv4stacklimits.cpp best regards, Ulf Hermann ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Default stack size of QThread
Thanks for your feedback. As we donot set any stack size for QThread and it looks like it runs out of default stack size limit during long running operation. Hence would like to measure the cumulative stack variables used in a thread so as to set stack size of QThread accordingly. On Mon, 28 Aug, 2023, 22:37 Thiago Macieira, wrote: > On Monday, 28 August 2023 05:08:25 PDT Ramakanth Kesireddy wrote: > > Hi, > > > > We are using Qt 5.15.x through yocto Dunfell on embedded Linux. > > > > Any thoughts on default stack thread size of QThread would be great if it > > would be 1-2MB. > > Why do you want that? This either indicates you don't understand how > memory > management works on Linux or you have a different problem that needs > fixing. > > If you really want this, then QThread doesn't enforce any limit. Please > consult the documentation for the pthread_create() function on how how it > determines the default stack size. For glibc, it uses the RLIMIT_STACK > resource limit. > > -- > Thiago Macieira - thiago.macieira (AT) intel.com > Cloud Software Architect - Intel DCAI Cloud Engineering > ___ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest > ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Default stack size of QThread
On Monday, 28 August 2023 10:05:14 PDT Thiago Macieira wrote: > If you really want this, then QThread doesn't enforce any limit. Please > consult the documentation for the pthread_create() function on how how it > determines the default stack size. For glibc, it uses the RLIMIT_STACK > resource limit. I meant, "by default". Yes you can change the stack size using QThread::setStackSize(), but the default of QThread is 0, so it's whatever the underlying implementation chooses. Since you're using Yocto, if this really matters to you, just change the underlying implementation or Qt. But please answer the question on why you think you need this. -- Thiago Macieira - thiago.macieira (AT) intel.com Cloud Software Architect - Intel DCAI Cloud Engineering smime.p7s Description: S/MIME cryptographic signature ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Default stack size of QThread
On Monday, 28 August 2023 05:08:25 PDT Ramakanth Kesireddy wrote: > Hi, > > We are using Qt 5.15.x through yocto Dunfell on embedded Linux. > > Any thoughts on default stack thread size of QThread would be great if it > would be 1-2MB. Why do you want that? This either indicates you don't understand how memory management works on Linux or you have a different problem that needs fixing. If you really want this, then QThread doesn't enforce any limit. Please consult the documentation for the pthread_create() function on how how it determines the default stack size. For glibc, it uses the RLIMIT_STACK resource limit. -- Thiago Macieira - thiago.macieira (AT) intel.com Cloud Software Architect - Intel DCAI Cloud Engineering smime.p7s Description: S/MIME cryptographic signature ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
[Interest] Default stack size of QThread
Hi, We are using Qt 5.15.x through yocto Dunfell on embedded Linux. Any thoughts on default stack thread size of QThread would be great if it would be 1-2MB. Best Regards, Ramakanth ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
