Re: [Intel-gfx] Improvements and fixes for Intel ddx swap scheduling/timestamping.
On Sun, Oct 07, 2012 at 08:38:07AM +0200, Mario Kleiner wrote: Hi, a series of three patches to improve the dri2 swap scheduling and timestamping for the current intel ddx. The first one enables proper OML_sync_control timestamping while triple-buffering is enabled and XOrg 1.12+ with DRI2SwapLimit support is in use. So far, timestamping was unuseable with triple-buffering, only worked with double-buffering. The second one repairs the broken pageflip swap scheduling, which is apparently in a frightening state for timing sensitive apps since a year, due to a tiny but really ugly bug. In a perfect implementation of Murphy's law, the same commit that broke the scheduling also disabled the builtin correctness checks that were supposed to catch such bugs. The third one proposes to revert 'SwapBuffersWait' to its old behaviour where it didn't affect pageflipping. I just can't think of a case where the current behaviour makes any sense, not even for benchmarking? But maybe i'm overlooking something. All patches were tested against an Intel 945-GME gpu. I don't really care about the 'SwapBuffersWait' patch one way or the other, but the first two are crucial to make the intel ddx useable in a painless and safe way again for users of timing sensitive applications. This kind of regressions suck. Are there no tests (in piglit) that check OML buffer swap and timestamping behaviour at least internally? Or could I volunteer you to create that? Toghether with the new kernel flip tests this should catch any further such regressions ... -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] Improvements and fixes for Intel ddx swap scheduling/timestamping.
Daniel Vetter dan...@ffwll.ch writes: On Sun, Oct 07, 2012 at 08:38:07AM +0200, Mario Kleiner wrote: Hi, a series of three patches to improve the dri2 swap scheduling and timestamping for the current intel ddx. The first one enables proper OML_sync_control timestamping while triple-buffering is enabled and XOrg 1.12+ with DRI2SwapLimit support is in use. So far, timestamping was unuseable with triple-buffering, only worked with double-buffering. The second one repairs the broken pageflip swap scheduling, which is apparently in a frightening state for timing sensitive apps since a year, due to a tiny but really ugly bug. In a perfect implementation of Murphy's law, the same commit that broke the scheduling also disabled the builtin correctness checks that were supposed to catch such bugs. The third one proposes to revert 'SwapBuffersWait' to its old behaviour where it didn't affect pageflipping. I just can't think of a case where the current behaviour makes any sense, not even for benchmarking? But maybe i'm overlooking something. All patches were tested against an Intel 945-GME gpu. I don't really care about the 'SwapBuffersWait' patch one way or the other, but the first two are crucial to make the intel ddx useable in a painless and safe way again for users of timing sensitive applications. This kind of regressions suck. Are there no tests (in piglit) that check OML buffer swap and timestamping behaviour at least internally? Or could I volunteer you to create that? Toghether with the new kernel flip tests this should catch any further such regressions ... I posted a first couple of tests that try to just hit the API for the most part, but I don't test the MSCs or wall-time timing behavior. pgp34K91aczHH.pgp Description: PGP signature ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] Improvements and fixes for Intel ddx swap scheduling/timestamping.
On 08.10.12 18:08, Eric Anholt wrote: Daniel Vetter dan...@ffwll.ch writes: On Sun, Oct 07, 2012 at 08:38:07AM +0200, Mario Kleiner wrote: Hi, a series of three patches to improve the dri2 swap scheduling and timestamping for the current intel ddx. The first one enables proper OML_sync_control timestamping while triple-buffering is enabled and XOrg 1.12+ with DRI2SwapLimit support is in use. So far, timestamping was unuseable with triple-buffering, only worked with double-buffering. The second one repairs the broken pageflip swap scheduling, which is apparently in a frightening state for timing sensitive apps since a year, due to a tiny but really ugly bug. In a perfect implementation of Murphy's law, the same commit that broke the scheduling also disabled the builtin correctness checks that were supposed to catch such bugs. The third one proposes to revert 'SwapBuffersWait' to its old behaviour where it didn't affect pageflipping. I just can't think of a case where the current behaviour makes any sense, not even for benchmarking? But maybe i'm overlooking something. All patches were tested against an Intel 945-GME gpu. I don't really care about the 'SwapBuffersWait' patch one way or the other, but the first two are crucial to make the intel ddx useable in a painless and safe way again for users of timing sensitive applications. This kind of regressions suck. Are there no tests (in piglit) that check OML buffer swap and timestamping behaviour at least internally? Or could I volunteer you to create that? Toghether with the new kernel flip tests this should catch any further such regressions ... I posted a first couple of tests that try to just hit the API for the most part, but I don't test the MSCs or wall-time timing behavior. I will also have a look at piglit at one of the next weekends and see what i can do. I haven't tried piglit yet, but that would make sense if it can catch bugs before a driver release. My own toolkit has some builtin online tests for the bugs or limitations that are so far known, but that can only catch driver bugs after a broken driver is released. Here is what i currently test for, starting at the line in the link (paranoia at work): https://github.com/kleinerm/Psychtoolbox-3/blob/master/PsychSourceGL/Source/Linux/Screen/PsychWindowGlue.c#L1098 -mario ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
[Intel-gfx] Improvements and fixes for Intel ddx swap scheduling/timestamping.
Hi, a series of three patches to improve the dri2 swap scheduling and timestamping for the current intel ddx. The first one enables proper OML_sync_control timestamping while triple-buffering is enabled and XOrg 1.12+ with DRI2SwapLimit support is in use. So far, timestamping was unuseable with triple-buffering, only worked with double-buffering. The second one repairs the broken pageflip swap scheduling, which is apparently in a frightening state for timing sensitive apps since a year, due to a tiny but really ugly bug. In a perfect implementation of Murphy's law, the same commit that broke the scheduling also disabled the builtin correctness checks that were supposed to catch such bugs. The third one proposes to revert 'SwapBuffersWait' to its old behaviour where it didn't affect pageflipping. I just can't think of a case where the current behaviour makes any sense, not even for benchmarking? But maybe i'm overlooking something. All patches were tested against an Intel 945-GME gpu. I don't really care about the 'SwapBuffersWait' patch one way or the other, but the first two are crucial to make the intel ddx useable in a painless and safe way again for users of timing sensitive applications. Thanks, -mario ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
