On Tue, Feb 19, 2013 at 10:24:41AM -0500, Brian Foster wrote: > The updated speculative preallocation algorithm for handling sparse > files can becomes less effective in situations with a high number of > concurrent, sequential writers. The number of writers and amount of > available RAM affect the writeback bandwidth slicing algorithm, > which in turn affects the block allocation pattern of XFS. For > example, running 32 sequential writers on a system with 32GB RAM, > preallocs become fixed at a value of around 128MB (instead of > steadily increasing to the 8GB maximum as sequential writes > proceed). > > Update the speculative prealloc heuristic to base the size of the > next prealloc on double the size of the preceding extent. This > preserves the original aggressive speculative preallocation > behavior and continues to accomodate sparse files at a slight cost > of increasing the size of preallocated data regions following holes > of sparse files. > > Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> > Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx> Excuse me. This is the version I applied. Not v1. -Ben _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
