Messages in this thread |  | | Date | Wed, 7 Nov 2001 15:02:29 -0500 (EST) | From | Alexander Viro <> | Subject | Re: [Ext2-devel] ext2/ialloc.c cleanup |
| |
On Wed, 7 Nov 2001, Andreas Dilger wrote:
> Minor nits, from my changes to this same function: > 1) please replace use of "i" for best block group in find_cg_*, to > something better like "group", just for clarity.
Consider that done.
> 2) in find_cg_*, when you fail the quadratic search, the linear search > should skip groups that were previously checked in the quadratic search, > with slight changes to both loops:
I'm not actually sure that it's a good thing. The different between the sequences we do is that I do n n+1 n+3 n+7 ... n+2 (linear) and you do n n+1 n+2 n+4 n+8 ... n+3 (linear) which has slightly worse properties. You avoid duplicated check on n+3, but lose a very nice property - shifting the old sequence is guaranteed not to have many intersections with original in the beginning (distances between elements do not repeat). With your sequence it's no longer true.
> 3) I know that "cylinder groups" were used in old FFS/whatever implementation, > but all of the ext2 code/documentation refers to these as block groups. > Can you stick with that for ext2 (e.g. gdp, not cg; bg_foo, not cg_foo)?
Ehh... Try to read that aloud. Maybe it's just me, but "gdp" sounds (and looks) bad...
> 4) sbi can be gotten by "EXT2_SB(sb)".
True, consider that done.
Right now I'm doing alternative strategy for directory allocation, as soon as I finish that I'll put the result on usual place.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |