Messages in this thread | | | From | Jesse Barnes <> | Subject | Re: [PATCH] Export kmap_atomic_pfn for DRM-GEM. | Date | Mon, 22 Sep 2008 10:59:54 -0700 |
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On Wednesday, August 27, 2008 5:22 pm Nick Piggin wrote: > > However, when other DRM drivers get around to doing memory management, > > I'm sure they'll also be interested in an ioremap_wc that doesn't eat > > ipi costs. For us, the ipis for flushing were eating over 10% of CPU > > time. If your patch series cuts that cost, we could drop this piece at > > that point. > > It can cut the cost quite significantly on normal vmap/vunmap loads I > tested. Whether it will work as well on your workload, I don't know > but I would have liked to find out. I raised this issue quite a while > back, so I'm disappointed it had not been tried...
I think Eric has code with the vmap changes now?
Given our discussions at KS/Plumbers would you be ok with acking these patches? Or do you want a repost so you can check out the vmap stuff?
After talking a bit more about it, I think we agreed that the ioctl interface is actually a better approach then trying to shoehorn this stuff into system calls, so aside from the vmap code (which could be done in 2.6.29 or whenever the vmap stuff lands) I think this patchset is pretty close to what we want in drm-next now...
Thanks, Jesse
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