On 06/09/16 01:59 PM, Jason Ekstrand wrote: > On Sep 5, 2016 8:43 PM, "Michel Dänzer" <mic...@daenzer.net > <mailto:mic...@daenzer.net>> wrote: >> >> On 06/09/16 12:08 PM, Jason Ekstrand wrote: >> > On Mon, Sep 5, 2016 at 7:39 PM, Michel Dänzer <mic...@daenzer.net > <mailto:mic...@daenzer.net> >> > <mailto:mic...@daenzer.net <mailto:mic...@daenzer.net>>> wrote: >> > >> > From: Michel Dänzer <michel.daen...@amd.com > <mailto:michel.daen...@amd.com> >> > <mailto:michel.daen...@amd.com <mailto:michel.daen...@amd.com>>> >> > >> > This can make a significant difference for performance with some > extreme >> > test cases such as vblank_mode=0 glxgears. >> > >> > Fixes: 1e3218bc5ba2 ("loader/dri3: Overhaul dri3_update_num_back") >> > Cc: "12.0 11.2" <mesa-sta...@lists.freedesktop.org > <mailto:mesa-sta...@lists.freedesktop.org> >> > <mailto:mesa-sta...@lists.freedesktop.org > <mailto:mesa-sta...@lists.freedesktop.org>>> >> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97549 >> > <https://bugs.freedesktop.org/show_bug.cgi?id=97549> >> > Signed-off-by: Michel Dänzer <michel.daen...@amd.com > <mailto:michel.daen...@amd.com> >> > <mailto:michel.daen...@amd.com <mailto:michel.daen...@amd.com>>> >> > --- >> > >> > I could swear I tested vblank_mode=0 glxgears with my previous > change >> > and couldn't measure any difference, but I can now, so I must have >> > messed up my previous testing somehow... Apologies for any > inconvenience >> > this caused. >> > >> > src/loader/loader_dri3_helper.c | 4 +--- >> > 1 file changed, 1 insertion(+), 3 deletions(-) >> > >> > diff --git a/src/loader/loader_dri3_helper.c >> > b/src/loader/loader_dri3_helper.c >> > index 86ae5ae..3ce0352 100644 >> > --- a/src/loader/loader_dri3_helper.c >> > +++ b/src/loader/loader_dri3_helper.c >> > @@ -70,10 +70,8 @@ dri3_update_num_back(struct loader_dri3_drawable >> > *draw) >> > { >> > if (draw->flipping) >> > draw->num_back = 3; >> > - else if (draw->vtable->get_swap_interval(draw) != 0) >> > - draw->num_back = 2; >> > else >> > - draw->num_back = 1; >> > + draw->num_back = 2; >> > >> > >> > With this change, the function is logically identical to the old >> > function with the async flipping case removed. >> >> Not sure what you mean exactly, but I hope we can agree that the code is >> easier to understand and reason about now. :) > > I mean that you original patch made two functional changes: One was to > drop quadbuffering
As I explained, there was really no quad-buffering in the first place. > and the second was to single-buffer in the swapinterval==0 case. > This effectively reverts the second functional change while leaving > the first intact. That's not the only remaining change either. E.g. before my changes, flipping with swap interval > 0 was using only two buffers, now it's three. (That was actually the main motivation for my first change) -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
