[email protected] (YAMAMOTO Takashi) wrote: > hi, > > what's the status of emap and pipe? >
If I remember correctly, I could not get real performance improvement of pipe with UVM emap. Higher chances are that it would improve socket performance. Also, pipe has direct I/O disabled (PIPE_NODIRECT) due to some rare lock-ups when switching between direct/buffered. AFAIK, we have this bug since netbsd-3 times or even earlier. However, I tend to question whether UVM emap was a right approach to the problem. For amd64, we should definitely have a direct mapping of kernel space (I was planning to revive the patch written by chs@, but ran out of time) and encourage our users to use amd64 instead of i386. Most other architectures have a segment for direct mapping. I wonder if we could help i386 with large pages for kernel space.. -- Mindaugas
