On 10 July 2017 at 13:21, Martin Thompson <mjpt...@gmail.com> wrote: > Are you running recent MacOS with APFS which supports sparse files? >
If this is of any interest, my OS version is Darwin MacBook-Pro.local 16.6.0 Darwin Kernel Version 16.6.0: Fri Apr 14 16:21:16 PDT 2017; root:xnu-3789.60.24~6/RELEASE_X86_64 x86_64 (i. e. very recent) When considering an algorithm for pre-touch ahead it is often useful to > consider rate to determine who far ahead you should be pre-touching. > Logically the higher the rate the longer pre-touch chunk should be, but when I did pretouch of the whole 32 MB buffers (instead of 1 MB chunks) pauses were even worse. > When pre-touching then it can be better with a positional write of a byte, > i.e. use https://docs.oracle.com/javase/7/docs/api/java/nio/ > channels/FileChannel.html#write(java.nio.ByteBuffer,%20long) which should > map to pwrite() on Linux. This will be a safepoint whereas the mapped > buffer write will not be. > Thanks, will try -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to mechanical-sympathy+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
