Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Thiago Macieira
Em terça-feira, 7 de março de 2017, às 22:28:11 CET, Simon Hausmann escreveu: > I understand that this is in the context of Linux without overcommit. Which is exactly the situation in which forking should be fast. If it wasn't overcommitting, then the kernel would try and reserve the pages,

Re: [Development] syncqt.pl in C++

2017-03-07 Thread André Somers
Op 07/03/2017 om 22:43 schreef Richard Moore: > > > You're right. My wording above was misleading, I wasn't present > myself. This is what I remembered people telling me afterwards. > > Here are the session > notes: https://wiki.qt.io/Qt_build_systems_at_QtCon_2016 >

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Corentin
For what it's worth, as a Qt user, QBS was, last time I checked missing some features, like non-transitive compilatuons flags, platform support and documentation. That being said, in the past few years, I wrote some makefiles, some cmake projects. I've used WAF, qmake... QBS is the best C++

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Richard Moore
> > > You're right. My wording above was misleading, I wasn't present myself. > This is what I remembered people telling me afterwards. > > Here are the session notes: https://wiki.qt.io/Qt_ > build_systems_at_QtCon_2016 > > ​Yep, there's also a video. My recollection is that there was a small

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Lars Knoll
On 7 Mar 2017, at 22:24, Richard Moore > wrote: On 7 March 2017 at 21:21, Lars Knoll > wrote: > On 7 Mar 2017, at 21:54, Thiago Macieira > > wrote: > > Em

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Simon Hausmann
I understand that this is in the context of Linux without overcommit. Simon > On 7 Mar 2017, at 22:05, Thiago Macieira wrote: > > Em terça-feira, 7 de março de 2017, às 17:53:41 CET, René J.V. Bertin > escreveu: >> One tends to forget (I do at least) that spawning a

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Richard Moore
On 7 March 2017 at 21:21, Lars Knoll wrote: > > > On 7 Mar 2017, at 21:54, Thiago Macieira > wrote: > > > > Em terça-feira, 7 de março de 2017, às 21:37:46 CET, Richard Moore > escreveu: > >>> The Qt Company has now very recently made a decision to

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Lars Knoll
> On 7 Mar 2017, at 21:54, Thiago Macieira wrote: > > Em terça-feira, 7 de março de 2017, às 21:37:46 CET, Richard Moore escreveu: >>> The Qt Company has now very recently made a decision to now go and invest >>> the man power required to turn qbs into a product we

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Thiago Macieira
Em terça-feira, 7 de março de 2017, às 17:53:41 CET, René J.V. Bertin escreveu: > One tends to forget (I do at least) that spawning a little helper process > can be quite expensive, sometimes prohibitively so. Makes you wonder what > kind of cross-platform alternatives there are! It shouldn't

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Thiago Macieira
Em terça-feira, 7 de março de 2017, às 14:32:13 CET, Christian Kandeler escreveu: > This kind of stuff seems to happen when the parent process has allocated > a lot of memory. I haven't debugged into it, but one idea might be that > the page tables themselves get to a non-trivial size and thus

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Thiago Macieira
Em terça-feira, 7 de março de 2017, às 21:37:46 CET, Richard Moore escreveu: > > The Qt Company has now very recently made a decision to now go and invest > > the man power required to turn qbs into a product we can fully support in > > the future. This decision comes from the fact that we see

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Richard Moore
On 7 March 2017 at 19:12, Lars Knoll wrote: > Hi, > > Thiago's right that there has not been a formal decision in the Qt project > about the build system to use for Qt 6. So saying qbs will be the build > system for Qt 6 is getting a bit ahead of things. > > But we have had

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Jake Petroules
> On Mar 7, 2017, at 8:47 AM, Wolfgang Baron wrote: > > On 7 Mar 2017, at 08:11, Thiago Macieira > wrote: > > > There has been no discussion of qbs. Therefore, there is no > > decision on what to use for Qt 6. It might be cmake or qmake. >

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread René J . V . Bertin
On Tuesday March 07 2017 17:29:54 Kevin Funk wrote: > It's pulled in by the Grantlee library. KF5::TextEditor depends on > Qt5::Script > as well. There you have it, thanks Kevin. One tends to forget (I do at least) that spawning a little helper process can be quite expensive, sometimes

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Wolfgang Baron
On 7 Mar 2017, at 08:11, Thiago Macieira wrote: There has been no discussion of qbs. Therefore, there is no decision on what to use for Qt 6. It might be cmake or qmake. Then please start that discussion now. Qbs is a secret weapon for all developers trying to do

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Kevin Funk
On Tuesday, 7 March 2017 16:42:31 CET René J.V. Bertin wrote: > On Tuesday March 7 2017 14:20:18 Simon Hausmann wrote: > Hi > > > But for example if KDevelop ends up using QtScript and you're on a 64-bit > > system, then we end up allocating 2GB of address space, which the kernel > > has to copy

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread René J . V . Bertin
On Tuesday March 7 2017 14:20:18 Simon Hausmann wrote: Hi > But for example if KDevelop ends up using QtScript and you're on a 64-bit > system, then we end up allocating 2GB of address space, which the kernel has > to copy (in terms of page tables) when forking. It could be that you're short >

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Simon Hausmann
Hi, It would be interesting to see /proc//maps of the KDevelop process when fork fails. I would imagine - like Christian - that there is a shortage of memory mappings. It's odd that this is an issue, as there shouldn't be big memory mappings _usually_. But for example if KDevelop ends up

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Christian Kandeler
On 03/07/2017 02:54 PM, René J. V. Bertin wrote: >> This kind of stuff seems to happen when the parent process has allocated >> a lot of memory. I haven't debugged into it, but one idea might be that > > What is a lot here? Typical usage for one of the KDevelop sessions that tends > to > be

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread René J . V . Bertin
Christian Kandeler wrote: > This kind of stuff seems to happen when the parent process has allocated > a lot of memory. I haven't debugged into it, but one idea might be that What is a lot here? Typical usage for one of the KDevelop sessions that tends to be affected is around 70Mb total

Re: [Development] QProcess fork() failure and overcommit

2017-03-07 Thread Christian Kandeler
On 03/07/2017 02:04 PM, René J.V. Bertin wrote: > I have a bit of an intriguing issue I hope someone here could help me > understand. If not, sorry for the noise. > > I'm seeing occasional QProcess failures where QProcess:waitForStarted() fails > and gives rise to errors like > >

Re: [Development] Qt5.8 qdbuscpp2xml broken for kde baloo?

2017-03-07 Thread Andreas Müller via Development
On Tue, Mar 7, 2017 at 2:22 PM, Andreas Müller wrote: > On Fri, Feb 10, 2017 at 11:19 AM, Andreas Müller > wrote: >> Hi, >> >> I am cross building Qt and KDE with yocto environment. After Update to >> Qt 5.8 the package baloo from KDE

Re: [Development] Qt5.8 qdbuscpp2xml broken for kde baloo?

2017-03-07 Thread Andreas Müller via Development
On Fri, Feb 10, 2017 at 11:19 AM, Andreas Müller wrote: > Hi, > > I am cross building Qt and KDE with yocto environment. After Update to > Qt 5.8 the package baloo from KDE KF5 is broken. After investigation I > found that qdbuscpp2xml 5.8 build misses some public

[Development] QProcess fork() failure and overcommit

2017-03-07 Thread René J . V . Bertin
Hi, I have a bit of an intriguing issue I hope someone here could help me understand. If not, sorry for the noise. I'm seeing occasional QProcess failures where QProcess:waitForStarted() fails and gives rise to errors like kdevplatform.vcs: "DVCSJob::start: git ls-files -- kclock.cpp failed

Re: [Development] Comparison of version numbers in qmake project files

2017-03-07 Thread Konstantin Tokarev
07.03.2017, 13:54, "Alexander Volkov" : > Hi, > > Need more reviewers for https://codereview.qt-project.org/#/c/181665/ > which adds test functions for comparing version numbers: > > versionNumberAtLeast(VERSION, 5.10.0) { >  ... > } > > versionNumberLessThan(VERSION,

[Development] Comparison of version numbers in qmake project files

2017-03-07 Thread Alexander Volkov
Hi, Need more reviewers for https://codereview.qt-project.org/#/c/181665/ which adds test functions for comparing version numbers: versionNumberAtLeast(VERSION, 5.10.0) { ... } versionNumberLessThan(VERSION, 5.10.0) { ... } There are two questions: 1. Whether to use Number in the

Re: [Development] syncqt.pl in C++

2017-03-07 Thread Thiago Macieira
Em terça-feira, 7 de março de 2017, às 08:16:14 CET, Simon Hausmann escreveu: > Hi, > > I for one would welcome a C++ rewrite of syncqt inside qmake to get rid of > the perl dependency. However I do not have the authority to approve such a > contribution. It is something we have talked about many