On Sun, Jul 22, 2007 at 10:24:37AM +0200, Peter Zijlstra wrote: > On Sun, 2007-07-22 at 16:10 +0800, Fengguang Wu wrote: > > > - It will avoid large-file-reads-thrashing-my-desktop problem, > > so most desktop users should like it. But sure there will be counter > > cases when a user want to keep the data cached. > > - File servers may hurt from it. Imagine a mp3/png file server. The > > files are large enough to trigger drop-behind, but small (and hot) > > enough to be cached. Also when a new fedora DVD iso is released, it > > may be cached for some days. These are only the obvious cases. > > > > So I opt for it being made tunable, safe, and turned off by default. > > I'm still not convinced (Rik wasn't either last time around). When these > files really are hot, they will be kept in memory due to them becoming > Active. > > Also, by scaling up the max readahead size it takes a larger file before > it starts dropping. If say this server has 4G of memory (not much at all > for a server) resulting in a 1M readahead window, the file needs to be > > ~2M before it starts drop behind.
[snip] > But I guess it takes someone to try this IRL before we can settle this > debate :-/ Yeah, some real workload numbers would help. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
