On Wed, Feb 09, 2005 at 03:20:11PM +0100, Hegedus Gabor wrote: > 2005-02-09, sze keltezéssel 14:13-kor Paul Warren ezt írta: > > On Wed, Feb 09, 2005 at 02:59:50PM +0100, Andreas Wohlfeld wrote: > > > Patch your host with skas and see that the temp files go to a tempfs > > > mount point (or mount /tmp with tempfs). This will make things a lot > > > faster. > > > > Can someone tell me what the tempfs trick achieves? My understanding > > was that it prevented the mmapped memory file from being swapped out. > > Does it do something more than that? > Hi! > > It is near to a ramdisk. And you put the uml ramfile to the ramdisk, so > it is in the real ram couse it is fast.
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 ------------------------------------------------------- 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
