<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="IT" link="#0563C1" vlink="#954F72"> <div class="WordSection1"> Good morning everyone, this is the first time I write on this mailing list cause we're having hard time to figure out an issue with the xorg windowing system; I hope this is the right place to ask for help, if it's not I'm sorry; I'd ask in that case where to submit this request. It happens that our application sometime get stuck calling an X primitive. The premise is that the same identical code has been running on a different platform for years (Ubuntu 14.04 with an NVidia video card), while on our newest architecture (Ubuntu 16.04 with an Intel video card) the trouble occurs a couple of time in a day; the application goes in hang in the context of a call to the xcb library while the cpu usage of server X (the Xorg application) raise up to 99-100 % !!!. This is the stack trace of the application getting stuck: Thread 1 (Thread 0xf3a5a840 (LWP 30325)): #0 0xf772ebe9 in __kernel_vsyscall () #1 0xf6b8fe7f in poll () from /lib/i386-linux-gnu/libc.so.6 #2 0xf69a141d in ?? () from /usr/lib/i386-linux-gnu/libxcb.so.1 #3 0xf69a31fb in ?? () from /usr/lib/i386-linux-gnu/libxcb.so.1 #4 0xf69a3359 in xcb_wait_for_reply () from /usr/lib/i386-linux-gnu/libxcb.so.1 #5 0xf75a0092 in _XReply () from /usr/lib/i386-linux-gnu/libX11.so.6 #6 0xf759b9af in XSync () from /usr/lib/i386-linux-gnu/libX11.so.6 #7 0xf75399d4 in ?? () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1 #8 0xf750edc7 in glXSwapBuffers () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1 #9 0x0843b096 in MxScreen::EndUpdate(bool, bool, bool) () #10 0x08118853 in CGraphics::EndUpdate(bool, bool) () #11 0x082015ae in VdbClient::Update(InfoPacketList&, VdbServer*) () #12 0x0820b232 in VdbServer::updateClients() () #13 0x0822ac10 in VdbServer::Update() () #14 0x0808ecd5 in safeVdbServerUpdate(VdbServer&) () #15 0x08090df6 in MxMain() () #16 0x08083d65 in main () This is instead the x server backtrace when the trouble occurs: [New LWP 1138] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". 0x00005628cfce0d43 in ?? () Thread 2 (Thread 0x7f533733f700 (LWP 1138)): pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 #1 0x00007f5337613569 in ?? () from /usr/lib/xorg/modules/drivers/intel_drv.so #2 0x00007f533b18b6ba in start_thread (arg=0x7f533733f700) at pthread_create.c:333 #3 0x00007f533b4a83dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 Thread 1 (Thread 0x7f533d649a00 (LWP 1137)): #0 0x00005628cfce0d43 in ?? () #1 0x00005628cfce0e7b in GetXIDRange () #2 0x00005628cfce0f37 in FakeClientID () #3 0x00005628cfdebbf0 in DRI2CreateDrawable2 () #4 0x00005628cfdedfb2 in ?? () #5 0x00005628cfcbbd9f in ?? () #6 0x00005628cfcbfe13 in ?? () #7 0x00007f533b3c1830 in __libc_start_main (main=0x5628cfcaa030, argc=9, argv=0x7fff448e80b8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff448e80a8) at ../csu/libc-start.c:291 The client application has more threads but just one deals with X windows system. Currently we're trying to install x server version 1.19 instead of the 'original' 1.18.04 Ubuntu 16.04 ship with (configuring some ppa repo) Any idea about what could be the reasons of this issue? Thank's in advance<o:p></o:p> <o:p> </o:p> Maurizio<o:p></o:p> <o:p> </o:p> </div> </body> </html>