On Thu, 20 Apr 2017 11:57:08 +0200 Marek Olšák <mar...@gmail.com> wrote:
> On Thu, Apr 20, 2017 at 10:28 AM, gregory hainaut > <gregory.hain...@gmail.com> wrote: > > On Thu, 20 Apr 2017 12:29:11 +0900 > > Michel Dänzer <mic...@daenzer.net> wrote: > > > >> On 20/04/17 01:54 AM, Gregory Hainaut wrote: > >> > Hello, > >> > > >> > Please find the latest version that include a small fix for hash > >> > deletion. I > >> > think the series is good now. Please review/ack it. > >> > >> I'm afraid I have to NACK it. As discussed in the v4 cover letter > >> thread, Mesa's glthread cannot make any libX11 API calls. > >> > >> > > > > Hello Michel, > > > > Just to be sure we are on the same line, let's me do a summary. > > > > PCSX2 does the following bad pattern > > 1/ no call to XInitThread > > 2/ XGetGeometry to get the size of the surface > > 3/ glDrawArray into the default framebuffer 0 (the window, I'm not sure how > > to call it) > > => which seem to call DRI2GetBuffersWithFormat under the hood. I guess > > to get the > > associated buffer of the window. > > > > > > So far it was (kind of) working fine because PCSX2 does tons of PBO > > transfer. So glthread > > was mostly synchronous. > > > > This series removes the (useless) PBO transfer synchronization. So now > > glthread is really > > asynchronous and the above bad pattern crash as expected. > > > > I didn't add any libX11 API call on the patches. And I don't think we can > > remvove the DRI stuff. > > > > Hum, I don't know what will be the impact on the perf but potentially we > > can force a synchronization > > when there is a draw to framebuffer 0. > > Can you send us the backtrace when DRI2GetBuffersWithFormat is called > by glDrawArrays? > > Marek Hello Marek, Michel, Here the full backtrace. #0 DRI2GetBuffersWithFormat (dpy=0xc6307e48, drawable=104857784, width=0xdef348c0, height=0xdef348c4, attachments=0xdcc15c88, count=1, outCount=0xdcc15c74) at dri2.c:464 #1 0xf05bac45 in dri2GetBuffersWithFormat (driDrawable=0xdef348a8, width=0xdef348c0, height=0xdef348c4, attachments=0xdcc15c88, count=1, out_count=0xdcc15c74, loaderPrivate=0xdefc6ef0) at dri2_glx.c:894 #2 0xe3ec3111 in dri2_drawable_get_buffers (count=<synthetic pointer>, atts=0xdef252f8, drawable=0xdefc7b08) at dri2.c:285 #3 dri2_allocate_textures (ctx=0xdef15928, drawable=0xdefc7b08, statts=0xdef252f8, statts_count=2) at dri2.c:480 #4 0xe3ebcbb0 in dri_st_framebuffer_validate (stctx=0xdef4ab10, stfbi=0xdefc7b08, statts=0xdef252f8, count=2, out=0xdcc15d78) at dri_drawable.c:83 #5 0xe3d37afc in st_framebuffer_validate (stfb=stfb@entry=0xdef24f58, st=st@entry=0xdef4ab10) at state_tracker/st_manager.c:189 Note "print stfb->Base->Name" give me 0 #6 0xe3d38649 in st_manager_validate_framebuffers (st=0xdef4ab10) at state_tracker/st_manager.c:869 #7 0xe3cd0580 in st_validate_state (st=0xdef4ab10, pipeline=ST_PIPELINE_RENDER) at state_tracker/st_atom.c:174 #8 0xe3cf935d in st_draw_vbo (ctx=0xdef7f8f8, prims=0xdcc15f40, nr_prims=1, ib=0x0, index_bounds_valid=1 '\001', min_index=39911, max_index=39914, tfb_vertcount=0x0, stream=0, indirect=0x0) at state_tracker/st_draw.c:191 #9 0xe3caf35e in vbo_draw_arrays (baseInstance=0, numInstances=1, count=4, start=39911, mode=5, ctx=0xdef7f8f8) at vbo/vbo_exec_array.c:427 #10 vbo_exec_DrawArrays (mode=5, start=39911, count=4) at vbo/vbo_exec_array.c:575 #11 0xe3be4f07 in _mesa_unmarshal_DrawArrays (ctx=0xdef7f8f8, cmd=0xc41574b0) at main/marshal_generated.c:26644 #12 _mesa_unmarshal_dispatch_cmd (ctx=0xdef7f8f8, cmd=0xc41574b0) at main/marshal_generated.c:42457 #13 0xe3ba8af0 in glthread_unmarshal_batch (release_batch=true, batch=0xc4157410, ctx=0xdef7f8f8) at main/glthread.c:64 #14 glthread_worker (data=0xdef7f8f8) at main/glthread.c:110 > If this DRI2GetBuffersWithFormat call results in libX11 API calls on the > glthread, that's a bug which needs to be fixed, either by moving the > DRI2GetBuffersWithFormat call to the main thread or (if possible) by > changing DRI2GetBuffersWithFormat to use XCB directly. Ok. On one hand, moving DRI2GetBuffersWithFormat to main thread won't be easy. I think we need to keep track of the current bound framebuffer on the app thread. So we can force a sync on gl operation that will access the framebuffer 0. On the other hand, GLX/XLIB/XCB interactions are quite foggy for me. It seem there already some xcb codes in various place typically EGL and the xcb_dri2 extension. So maybe there is a reason that code wasn't ported here. In particular, I saw this option in configure --enable-glx[=dri|xlib|gallium-xlib] enable the GLX library and choose an implementation [default=auto] > It sounds like the glthread bug above exists independently from this > patch series, which might just make it more likely to result in a crash. > I think it would still be better to fix the bug before landing this series. Yes it increases the probability to trigger the bug. Cheers, Gregory _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev