0dabe948f2
On some platforms, DMA mapping part of a page is more costly than copying bytes. Indeed, not involving the I/O MMU can help the RPC/RDMA transport scale better for tiny I/Os across more RDMA devices. This is because interaction with the I/O MMU is eliminated for each of these small I/Os. Without the explicit unmapping, the NIC no longer needs to do a costly internal TLB shoot down for buffers that are just a handful of bytes. Since pull-up is now a more a frequent operation, I've introduced a trace point in the pull-up path. It can be used for debugging or user-space tools that count pull-up frequency. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> |
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| .. | ||
| events | ||
| bpf_probe.h | ||
| define_trace.h | ||
| perf.h | ||
| syscall.h | ||
| trace_events.h | ||