On Thursday 17 January 2008 04:47, Abhishek Rai wrote: > > if Abhishek wants to pursue it, would be to pull in all of the > > indirect blocks when the file is opened, and create an in-memory > > extent tree that would speed up access to the file. It's rarely > > worth doing this without metaclustering, since it doesn't help for > > sequential I/O, only random I/O, but with metaclustering it would > > also be a win for sequential I/O. (This would also remove the > > minor performance degradation for sequential I/O imposed by > > metaclustering, and in fact improve it slightly for really big > > files.) > > Also, since the in memory extent tree will now occupy much less > space, we can keep them cached for a much longer time which will > improve performance of random reads. The new metaclustering patch is > more amenable to this trick since it reduces fragmentation thereby > reducing the number of extents. I can see value in preemptively loading indirect blocks into the buffer cache, but is building a second-order extent tree really worth the effort? Probing the buffer cache is very fast. Regards, Daniel - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
