[Chromium-users] Tilesort generates needed network traffic?

[James S. <arr...@gm...>]

Tilesort generates needed network traffic?

I have four Render SPUs and one Tilesort SPU. I have noticed that some
applications run slowly when they are rendering only to the local Render SPU
(ig. application, tilesort and render SPU are all on one host) while at the
same time using little CPU time. I replaced the 3 Render SPUs on remote
hosts with NOP SPUs on the localhost and found that CPU consumption went up
to 100% and applications ran faster. Suspecting that something about the
remote Render SPUs might be slowing down local rendering I inserted a Print
SPU on one of the remote nodes (note that the applications window is only on
the local X server, none of the remote X server/Render SPUs should be used).


I ran the atlantis text program and got this output:
LoadIdentity(  )
MatrixMode( GL_PROJECTION )
LoadMatrixf( [      1.37        0.00        0.00        0.00
                    0.00        2.75        0.00        0.00
                    0.00        0.00       -1.05       -1.00
                    0.00        0.00   -20512.82        0.00  ] )
MatrixMode( GL_MODELVIEW )
MatrixMode( GL_MODELVIEW )
PushMatrix(  )
LoadIdentity(  )
PopMatrix(  )
MatrixMode( GL_MODELVIEW )
Clear( 0x4100 )
LoadIdentity(  )
SwapBuffers( 1, 0 )
MakeCurrent( 1, 0, 1 )
LoadIdentity(  )
MatrixMode( GL_PROJECTION )
LoadMatrixf( [      1.37        0.00        0.00        0.00
                    0.00        2.75        0.00        0.00
                    0.00        0.00       -1.05       -1.00
                    0.00        0.00   -20512.82        0.00  ] )
MatrixMode( GL_MODELVIEW )
MatrixMode( GL_MODELVIEW )
PushMatrix(  )
LoadIdentity(  )
PopMatrix(  )
MatrixMode( GL_MODELVIEW )
Clear( 0x4100 )
LoadIdentity(  )
SwapBuffers( 1, 0 )
MakeCurrent( 1, 0, 1 )
LoadIdentity(  )
MatrixMode( GL_PROJECTION )
LoadMatrixf( [      1.37        0.00        0.00        0.00
                    0.00        2.75        0.00        0.00
                    0.00        0.00       -1.05       -1.00
                    0.00        0.00   -20512.82        0.00  ] )
MatrixMode( GL_MODELVIEW )
MatrixMode( GL_MODELVIEW )
PushMatrix(  )
LoadIdentity(  )
PopMatrix(  )
MatrixMode( GL_MODELVIEW )
Clear( 0x4100 )
LoadIdentity(  )
SwapBuffers( 1, 0 )
MakeCurrent( 1, 0, 1 )
LoadIdentity(  )
MatrixMode( GL_PROJECTION )
LoadMatrixf( [      1.37        0.00        0.00        0.00
                    0.00        2.75        0.00        0.00
                    0.00        0.00       -1.05       -1.00
                    0.00        0.00   -20512.82        0.00  ] )
MatrixMode( GL_MODELVIEW )
MatrixMode( GL_MODELVIEW )
PushMatrix(  )
LoadIdentity(  )
PopMatrix(  )

The Tilesort SPU is clearly sending data to the remote Render SPUs. Why? I
am using the Test All Tiles bucket mode, I am using auto_dlist_bbox,
lazy_send_dlists, and dlist_state_tracking. Why is this data being sent? How
can I eliminate it?

Thank you for your time,
James Steven Supancic III