The search algorithm does not work with the ctz approach at all, if there
is a free range of granules that does not fit a specific allocation (i.e.
the granule allocation is fragmented) it will cause an infinite loop as
the algorithm will try to find free space from the same (free) starting
granule, causing an infinite loop.
The clz approach works for all cases, it will find the last used granule
and the search will continue from the next free granule.
Also, offsetting a full GAT must be sizeof(gat[0] - 1), which is 31 in
this case. The reason is that the upper level search function increments
the value by +1.
The original code did the speedup only from the other direction (from end
to start). If the starting GAT index has reservations, they are not skipped
as a bunch, but instead the GAT is iterated bit-by-bit, causing a massive
performance issue.
Fix this by:
- Skipping full GATs right away
- Skipping all of the reserved bits from the starting GAT as a bunch
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
This patch refactors granule allocator to remove the 32 granules
limitation with the help of a gran_range_s structure and related
functions, see "mm_grantable.h" for details.
Below are the major functions explaining how this works:
- The gran_match() checks if a gran range all in the given state.
it gives last mismatch position when fails free range matching.
- The gran_search() tries to find the position of a free range.
It leverages last mismatch position from gran_match() to speed
up the search.
range size handling is mainly in gran_match() and gran_set_().
Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>
