>>> On 12/14/2011 at 07:20 AM, Jan Glauber <j...@linux.vnet.ibm.com> wrote:
> I can easily replace the mmap-memcpy with pread/pwrite. Unfortunately I > see huge performance drops if I do so. Currently I'm looking why the > system call variant costs so much more than mmap. Define "huge performance drops." I don't know that most people are going to be reading large files from a CMS minidisk. They're more likely to have large disks with lots of reasonably sized files. I suspect that some people are wanting to read very large files, but I don't know how many people, or how large the files are. Would it be possible to use pread for the FST, and then mmap-memcpy the actual file being read? I would find it far more understandable to need more memory to read a very large file than I would to just mount the file system. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
