On Wed, 2009-07-29 at 11:39 +0200, Thomas Hellström wrote: > 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 >
Ok code wasn't clear for me until i read ttm_global.c 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
