Hello, On Tue, Aug 13, 2013 at 03:13:08PM -0700, Kent Overstreet wrote: > If you're convinced this is a real issue though - how about
It is a real issue. Large order allocation is fine for optimization but shouldn't be depended upon. It does fail easily without compaction and compaction is heavy-ass operation which will blow up any minute performance advantage you might get from avoiding proper radix tree implementation. > IDA_SECTION_SIZE conditional on CONFIG_COMPACTION, so we use order 2 or > 3 allocations if CONFIG_COMPACTION=n? > > Then the max size toplevel array of pointers to segments would be > bigger, but that's only an issue when we're allocating up to near > INT_MAX ids, so it's difficult to see how _that_ would be an issue on a > small/embedded system... and we could even use vmalloc for that > allocation when the size of that array is > IDA_SECTION_SIZE. What about cyclic allocations then? This is natrually a radix tree problem. I don't know why you're resisting radix tree so much here. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
