Yes please! On Mon, Mar 16, 2015 at 12:43 PM, Zee Chen <zeo...@gmail.com> wrote:
> Of the existing BucketCache IOEngines, the FileIOEngine uses pread() to > copy data from kernel space to user space. This is a good choice when the > total working set size is much bigger than the available RAM and the > latency is dominated by IO access. However, when the entire working set is > small enough to fit in the RAM, using mmap() (and subsequent memcpy()) to > move data from kernel space to user space is faster. I have run some short > keyval gets tests and the results indicate a reduction of 2%-7% of kernel > CPU on my system, depending on the load. On the gets, the latency > histograms from mmap() are identical to those from pread(), but peak > throughput is close to 40% higher. > > Already tested the patch at Flurry. Anyone interested in reviewing the > patch? > > -Zee >
