<div dir="auto">All GL calls that might use libX11 must not be asynchronous within glthread.<div dir="auto"> </div><div dir="auto">Marek</div></div><div class="gmail_extra"> <div class="gmail_quote">On Apr 18, 2017 10:43 AM, "Gregory Hainaut" <<a href="mailto:gregory.hainaut@gmail.com">gregory.hainaut@gmail.com</a>> wrote: <blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hello Michel, As yes, I completely forgot about XInitThreads that must be it. I don't know how Nvidia manage to solve/force it. Anyway, I will fix my application. Thanks you for the info. <div class="elided-text"> On 4/18/17, Michel Dänzer <<a href="mailto:michel@daenzer.net">michel@daenzer.net</a>> wrote: > On 18/04/17 05:04 PM, gregory hainaut wrote: >> On Tue, 18 Apr 2017 08:51:24 +0200 >> gregory hainaut <<a href="mailto:gregory.hainaut@gmail.com">gregory.hainaut@gmail.com</a>> wrote: >> >>> On Mon, 17 Apr 2017 11:17:42 +0900 >>> Michel Dänzer <<a href="mailto:michel@daenzer.net">michel@daenzer.net</a>> wrote: >>> >>>> On 15/04/17 05:08 PM, gregory hainaut wrote: >>>>> On Sat, 15 Apr 2017 00:50:15 +0200 >>>>> Dieter Nützel <<a href="mailto:Dieter@nuetzel-hh.de">Dieter@nuetzel-hh.de</a>> wrote: >>>>> >>>>>> Am 14.04.2017 07:53, schrieb gregory hainaut: >>>>>>> On Fri, 14 Apr 2017 05:20:38 +0200 >>>>>>> Dieter Nützel <<a href="mailto:Dieter@nuetzel-hh.de">Dieter@nuetzel-hh.de</a>> wrote: >>>>>>> >>>>>>>> Am 14.04.2017 02:06, schrieb Dieter Nützel: >>>>>>>>> Hello Gregory, >>>>>>>>> >>>>>>>>> have you tested this with Mesa-demos/tests/pbo 'b' (benchmark)? >>>>>>>>> It result in crazy numbers and do not 'return' (one core stays @ >>>>>>>>> 100%). >>>>>>>> >>>>>>>> This is related to 'mesa_glthread=true'. >>>>>>>> If I disable (unset) it, all is fine after 'b' benchmark and 'pbo' >>>>>>>> exit >>>>>>>> with ESC as expeted. >>>>>>>> Crazy numbers stay, maybe counter overrun due to BIG numbers? ;-) >>>>>>>> >>>>>>>> Hope that helps. >>>>>>>> >>>>>>>> Dieter >>>>>>> >>>>>>> Hello Dieter, >>>>>>> >>>>>>> I tested the demo. There is a pseudo unrelated bug on the exit of >>>>>>> the >>>>>>> application. >>>>>>> >>>>>>> Mesa 17.1.0-devel implementation error: In _mesa_DeleteHashTable, >>>>>>> found non-freed data >>>>>>> >>>>>>> I will add a call to a _mesa_HashDeleteAll to fix it. >>>>>>> i.e. _mesa_HashDeleteAll(shared->ShadowBufferObjects, dummy_cb, >>>>>>> ctx); >>>>>>> >>>>>>> Now let's go back to the test behavior. The benchmarks will send 4s >>>>>>> of >>>>>>> asynchronous PBO transfer commands. And then will sync gl_thread >>>>>>> which >>>>>>> mean the application thread will be blocked until all PBO transfers >>>>>>> are >>>>>>> done. Gl_thread is faster to dispatch command so you will need to >>>>>>> wait >>>>>>> more before the thread goes back to real life. >>>>>>> >>>>>>> On my side, I need to wait around 45 seconds for 6 millions of >>>>>>> commands. >>>>>>> Result: 6,440,627 reads (gl thread on + PBO patches) >>>>>>> Result: 274,960 reads (gl thread off) >>>>>>> >>>>>>> In your case, "Result: 77,444,412 reads", I hope you're patient. >>>>>>> I think you must wait at least 10 minutes. >>>>>> >>>>>> Now, I was patient... >>>>>> Tried 2 times but after ~20 minutes I've killed it at first and >>>>>> attached >>>>>> gdb at it during second run. >>>>>> >>>>>> 0x00007fbda686e9a6 in pthread_cond_wait@@GLIBC_2.3.2 () from >>>>>> /lib64/libpthread.so.0 >>>>>> (gdb) bt >>>>>> #0 0x00007fbda686e9a6 in pthread_cond_wait@@GLIBC_2.3.2 () from >>>>>> /lib64/libpthread.so.0 >>>>>> #1 0x00007fbda5359453 in ?? () from /usr/local/lib/dri/r600_dri.so >>>>>> #2 0x00007fbda53661f4 in ?? () from /usr/local/lib/dri/r600_dri.so >>>>>> #3 0x0000000000401e18 in ?? () >>>>>> #4 0x00000000004028c7 in ?? () >>>>>> #5 0x00007fbda9925781 in fghRedrawWindow () from >>>>>> /usr/lib64/libglut.so.3 >>>>>> #6 0x00007fbda9925c08 in ?? () from /usr/lib64/libglut.so.3 >>>>>> #7 0x00007fbda9926cf9 in fgEnumWindows () from >>>>>> /usr/lib64/libglut.so.3 >>>>>> #8 0x00007fbda9925ce4 in glutMainLoopEvent () from >>>>>> /usr/lib64/libglut.so.3 >>>>>> #9 0x00007fbda9925d85 in glutMainLoop () from >>>>>> /usr/lib64/libglut.so.3 >>>>>> #10 0x00000000004019fc in ?? () >>>>>> #11 0x00007fbda957e541 in __libc_start_main () from /lib64/libc.so.6 >>>>>> #12 0x0000000000401afa in ?? () >>>>>> >>>>>> Should I do more or not worth it? >>>>>> >>>>>> Dieter >>>>> >>>>> Hello Dieter, >>>>> >>>>> To be honest, I don't konw how much time you need to wait. 77 millions >>>>> of >>>>> PBO transfer is quite huge. It depends on CPU/Memory/PCIe/VRAM/GPU >>>>> speed. >>>>> >>>>> Hum based on the image size (194*188*4), you need to approximately >>>>> transfer >>>>> 10522 GB of data from your GPU... Which is likely around 20 minutes if >>>>> PCIe run at full speed. Honestly I will let the application in >>>>> background >>>>> for a couple of hours. >>>> >>>> Basically, the application needs to be fixed not to emit an unlimited >>>> number of PBO transfers without doing anything which requires >>>> synchronizing to the transfers. >>>> >>>> >>> >>> Hello Michel, Timothy, Marek >>> >>> Yes, I think it should limit the number of transfer to a million. And >>> also uses fence to measure the PBO transfer. >>> >>> >>> However, I have found others crashes on PCSX2 with those patches. It >>> seems related to synchronization issue with GLX/DRI/X11. This series >>> removes most of the gl sync for PCSX2. So any missing sync will trigger >>> a crash. Or I got a not obvious bug in my patches. >>> >>> >>> Please find a backtrace below of a crash during a draw. I manage to get a >>> similar backtrace (i.e. >>> same exception in _XReply/dequeue_pending_request) when I call >>> XGetGeometry. >>> >>> >>> #4 0xf61ec777 in __GI___assert_fail (assertion=0xf6122099 >>> "!xcb_xlib_unknown_req_in_deq", file=0xf6122067 "../../src/xcb_io.c", >>> line=179, function=0xf612248d <__PRETTY_FUNCTION__.14063> >>> "dequeue_pending_request") >>> at assert.c:101 >>> #5 0xf60abbcd in dequeue_pending_request (dpy=<optimized out>, >>> req=<optimized out>) at ../../src/xcb_io.c:185 >>> #6 0xf60aca17 in _XReply (dpy=0xe8fdde80, rep=0xcd46b910, extra=6, >>> discard=0) at ../../src/xcb_io.c:639 >>> #7 0xf3bba8df in DRI2GetBuffersWithFormat (dpy=0xe8fdde80, >>> drawable=83886261, width=0xd8ba11e8, height=0xd8ba11ec, >>> attachments=0xcd46ba38, count=1, outCount=0xcd46ba24) at dri2.c:485 >>> #8 0xf3bbac45 in dri2GetBuffersWithFormat (driDrawable=0xd8ba11d0, >>> width=0xd8ba11e8, height=0xd8ba11ec, attachments=0xcd46ba38, count=1, >>> out_count=0xcd46ba24, loaderPrivate=0xf225df10) at dri2_glx.c:894 >>> #9 0xd555e121 in dri2_drawable_get_buffers (count=<synthetic pointer>, >>> atts=0xa15f8b20, drawable=0xa2e50a00) at dri2.c:285 >>> #10 dri2_allocate_textures (ctx=0xd8b98810, drawable=0xa2e50a00, >>> statts=0xa15f8b20, statts_count=2) at dri2.c:480 >>> #11 0xd5557bc0 in dri_st_framebuffer_validate (stctx=0x9df20900, >>> stfbi=0xa2e50a00, statts=0xa15f8b20, count=2, out=0xcd46bb80) at >>> dri_drawable.c:83 >>> #12 0xd533ae8a in st_framebuffer_validate (stfb=stfb@entry=0xa15f8780, >>> st=st@entry=0x9df20900) at state_tracker/st_manager.c:189 >>> >>> >>> I don't have any clue on the GLX/DRI/X11 interaction with OpenGL. If >>> someone have any idea, feel free to share :) >> >> If it can help, here the backtrace from XGetGeometry which I can "easily" >> trigger. I >> only hit once the above trace. Note that above trace was inside glthread >> whereas >> XGetGeometry is from the application thread. >> >> #4 0xf61ec777 in __GI___assert_fail (assertion=0xf6122099 >> "!xcb_xlib_unknown_req_in_deq", file=0xf6122067 "../../src/xcb_io.c", >> line=179, function=0xf612248d <__PRETTY_FUNCTION__.14063> >> "dequeue_pending_request") >> at assert.c:101 >> #5 0xf60abbcd in dequeue_pending_request (dpy=<optimized out>, >> req=<optimized out>) at ../../src/xcb_io.c:185 >> #6 0xf60aca17 in _XReply (dpy=0x8ad3ca80, rep=0xd637b89c, extra=6, >> discard=1) at ../../src/xcb_io.c:639 >> #7 0xf6090a9e in XGetGeometry (dpy=0x8ad3ca80, d=83886309, >> root=0xd637ba40, x=0xd637ba80, y=0xd637bac0, width=0xd637b980, >> height=0xd637b940, borderWidth=0xd637b9c0, depth=0xd637ba00) at >> ../../src/GetGeom.c:47 >> #8 0xe5d868b8 in GSWndOGL::GetClientRect (this=0xd8a6509c) at >> ../plugins/GSdx/GSWndOGL.cpp:219 > > So, unless the application made sure that XInitThreads was called before > any other libX11 APIs, and all libX11 API calls in the application and > in Mesa are guarded by XLockDisplay/XUnlockDisplay, this is invalid > libX11 API usage, and a crash is expected. > > BTW, in addition to what I wrote in my other post, I think this boils > down to: Mesa can only call any libX11 APIs from the main thread, not > from the glthread. > > In some cases, an alternative might be using XCB APIs directly instead > of libX11 APIs. > > > -- > Earthling Michel Dänzer | <a href="http://www.amd.com" rel="noreferrer" target="_blank">http://www.amd.com</a> > Libre software enthusiast | Mesa and X developer > _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> <a href="https://lists.freedesktop.org/mailman/listinfo/mesa-dev" rel="noreferrer" target="_blank">https://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </div></blockquote></div> </div>