> > The other big problem is scalability. Even if it was somehow possible > > to make this scheme work the IPIs for flushing would kill performance > > on any multi threaded client. Given perf is not multi-threaded today, but > > it doesn't seem a good idea to design the interface assuming no client ever > > will be. > > Well any mmap()ed interface that wants to swap buffers will have this > same problem.
There's no need to swap buffers in a sane design. The perf ring buffer or the ftrace buffer don't need this. There's no need for a PT buffer to do so either. > > You can restrict the TLB flushing to the threads that poll() on the > relevant events. This just means other threads will see old/partial > data, but that shouldn't be a problem as they shouldn't be looking in > the first place. Then we get incoherent processes. You're not serious about that are you? -Andi -- a...@linux.intel.com -- Speaking for myself only -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
