Jerome Glisse wrote: > On Tue, 2009-07-28 at 20:55 +0200, Thomas Hellström wrote: > >> Jerome Glisse skrev: >> >>> On Wed, 2009-07-22 at 10:37 +0200, Thomas Hellström wrote: >>> >>> >>>> TTM has a device struct per device and an optional global struct that is >>>> common for all devices and intended to be per subsystem. >>>> >>>> The only subsystem currently having a global structure is the memory >>>> accounting subsystem: >>>> struct ttm_mem_global >>>> >>>> >>> Thomas i don't think the way we init ttm_mem_global today make >>> it follow the 1 struct ttm_mem_global for everyone. I think it >>> should be initialized and refcounted by device struct. >>> >>> So on first device creation a ttm_mem_global is created and >>> then anytime a new device is created the refcount of ttm_mem_global >>> is increased. >>> >> Jerome, >> This is exactly what the current code intends to do. >> >> Are you seeing something different? >> > > I definitly don't see that :) In radeon we do create a structure > which hold the ttm_mem_global struct so it's not shared at all > it got inited & destroyed along the driver. This is why i think > it's better to remove the driver initialization and let bo_device > init path take care of initializing one and only one object which > can be shared by multiple driverttm_mem_global_inits. > > Which radeon struct is holding the ttm_mem_global struct?
The radeon code looks very similar to the openchrome code in which the struct ttm_mem_global is allocated at ttm_global.c, line 74 and freed at ttm_global.c, line 108 when its refcount has reached zero. So the device holds a struct ttm_global_reference that *only points* to the global item, and which is destroyed on device takedown. If there are more than one device pointing to the mem_global object, it won't get destroyed. So the code should be working perfectly fine unless there is a bug. > So what i propose is remove mem_glob parameter from : > ttm_bo_device_init, add a call to ttm_mem_global_init in > ttm_bo_device_init Nope, The ttm_mem_global object is used by other ttm subsystems (fencing, user-space objects), so that can't be done. > and add some static refcount in ttm_memory.c > if refcount = 0 then ttm_mem_global_init create a ttm_mem_global > struct and initialize things, if refcount > 0 then it gives > back the already initialized ttm_mem_global. > > This is exactly what ttm_global was created to do, and what it hopefully does. If you create two radeon devices the ttm_mem_global object should be the same, even though the global references pointing to it are of course different. Have you actually tried this? /Thomas > Of course we unref with ttm_mem_global_release and destroy > once refcount reach 0. > > Cheers, > Jerome > > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
