>>> Paul Warren <[EMAIL PROTECTED]> 02/09/05 07:12AM >>> > Right, but the memory is mmapped to that file. My understanding is that > the memory will only be synced with the disk when either (a) msync (or > munmap) gets called or (b) the kernel has nothing better to do.
> I'm assuming that (a) doesn't happen, and I wouldn't expect (b) to > happen if the I/O system is otherwise engaged, so I don't understand > where the performance gain comes from - it should all be in RAM anyway. Paul, Assuming that you assessment is correct, what happens when: 1. The system is idle (say, for 4 seconds). 2. The host decides to swap-out the guest kernel and memory. 3. Your user, in the middle of looking at his programming book, starts typing again. tmpfs resolves a LOT of the performance issues. Also, did you compile your guest kernel with 'CONFIG_BLK_DEV_UBD_SYNC'? I believe this option forces synchronous disk activity (to preserve your data). However, someone else might have a better idea concerning this. Tony ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
