On Sat, Nov 26, 2005 at 11:17:55AM +0800, Wu Fengguang wrote: > On Fri, Nov 25, 2005 at 04:43:17PM +0100, Diego Calleja wrote: > > Recently, a openoffice hacker wrote in his blog that the kernel was > > culprit of applications not starting as fast as in other systems. > > Most of the reasons he gave were wrong, but there was a interesting > > one: When you start your system, you've lots of free memory. Since > > you have lots of memory, he said it was reasonable to expect that > > kernel would readahead *heavily* everything it can to fill that > > memory as soon as possible (hoping that what you readahead'ed was > > part of the kde/gnome/openoffice libraries etc) and go back to the > > normal behaviour when your free memory is used by caches etc. > > "Teorically" it looks like a nice heuristic for desktops. Does > > adaptative readahead does something like this? > > It's interesting ;) > In fact some distributions do have a read-ahead script to preload files on > startup. The readahead system call should be enough for this purpose: > > NAME > readahead - perform file readahead into page cache posix_fadvise() with POSIX_FADV_WILLNEED hint? The specified data will be accessed in the near future. -- Tomasz Torcz Morality must always be based on practicality. [email protected] -- Baron Vladimir Harkonnen
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