This is a snapshot of my current work on PTE accessors and mmu_gather. It's not complete but it should show the direction I'm heading toward.
The main goals are: - Make mmu_gather used for all page table walk operations that also need to invalidate TLB entries, thus obsoleting flush_tlb_range() and flush_tlb_mm() as generic APIs to the TLB flushing. - Make mmu_gather stack based. The cleans quite a bit of stuff up, and once fully done, should allow to reduce latencies caused by the need to use get_cpu() for a long time. - Make mmu_gather more flexible so that archs who need to do more than what the standard implementation does don't have to copy all of it and do their own implementation. - Make mmu_gather suitable for batching on powerpc :-) This involves mostly adding a hook before PTE pages are unlocked and some work on the interaction between PTE accessors and tlb_remove_tlb_entry() - Remove other remaings of flush_tlb_*, keeping only for now flush_tlb_kernel_range() which will be harder to "fix" (provided we want to do it at all) - Go through all remaining page table accessors, remove all the unused ones (there's still a few), there should be only a handful left and redo the documentation accordingly. These goals are _NOT_ yet met by this patch serie and some of the bits in there may want to be done a bit differently. As I did the patches, and hacked various archs, I got a better visibility on what is done and why and thus some of my initial directions end up not looking so good. Most notably, the MMF_DEAD flag doesn't sound like such a good idea anymore and I'm considering instead replacing ptep_get_and_clear() and tlb_remove_tlb_entry() with a version that takes the batch as an argument. Also, I haven't fully moved the batch off the per-cpu, only "part 1" is there at this stage. However, I'll be travelling for a while and won't have much time to work on it until I'm back mid september, so I decided now was a good time to post what I have for comments and discussions on the approach taken. Cheers, Ben. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
