Messages in this thread | | | Date | Tue, 20 Nov 2012 17:59:57 +1000 | Subject | Re: [PATCH 3/4] drm/ttm, drm/vmwgfx: Use RCU locking for object lookups v3 | From | Dave Airlie <> |
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On Tue, Nov 20, 2012 at 4:44 PM, Thomas Hellstrom <thellstrom@vmware.com> wrote: > On 11/20/2012 07:19 AM, Dave Airlie wrote: >> >> On Tue, Nov 6, 2012 at 9:31 PM, Thomas Hellstrom <thellstrom@vmware.com> >> wrote: >>> >>> The mostly used lookup+get put+potential_destroy path of TTM objects >>> is converted to use RCU locks. This will substantially decrease the >>> amount >>> of locked bus cycles during normal operation. >>> Since we use kfree_rcu to free the objects, no rcu synchronization is >>> needed >>> at module unload time. >> >> As this is the first use of RCU in a drm driver from what I can see, >> let me remind that the >> RCU patent agreement AFAIK only covers GPL works. >> >> So non-GPL or other OSes porting this code should take not of this. >> >> Dave. > > > From VMware's side this won't be a problem, since other VMware kernel > modules (VMCI IIRC) use RCU. > > In any case I have a new version of the "vmwgfx optimization" patch series > that mostly add documentation and > annotation (by using a drm_ht_xxx_rcu) interface for hashtab, after an > internal review by Dmitry Torkov. I see you've already > applied the original patch series. Do you want me to send out the new one or > rebase it against current drm-next?
Can you rebase it on top of -next?
Dave.
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