Aneesh Kumar K.V wrote: > The locality group prealloc list is freed only when there is a block allocation > failure. This can result in large number of per cpu locality group prealloc space > and also make the ext4_mb_use_preallocated expensive. Add a tunable max_lg_prealloc > which default to 1000. If we have more than 1000 Per-CPU prealloc space and if we > fail to find a suitable prealloc space during allocation we will now free all > the prealloc space in the locality group. It looks like this helps, but does not fare as well as the "perfectly tuned" default (where the prealloc size is a multiple of the 20k/5 block file size used in the test.) I've added a plot of a delalloc run with your patch to the graph at: http://people.redhat.com/esandeen/ext4/fs_mark.png -Eric -- 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
