Merge r6112:
Changes resulting from porting to AIX5:
- Auxiliary primary map handling has been redone, so that the
performance penalty for hitting memory above the magic 32G limit is
much reduced, and also the number of usable maps is limited only by
how much memory is available. The current code has been tested on
64-bit AIX for processes up to about 8GB in size.
The auxiliary primary maps are now stored in an OSet, "auxmap_L2".
However, looking up in an OSet for each memory reference is
expensive. So the OSet is 'fronted' by 24-entry array which holds
pointers to the 24 most recently used auxiliary primary maps.
Accesses to this array are made faster by incrementally rearranging
it on every lookup (if the requested map is found in the array, it
is moved one element closer to the start of the array).
Logically speaking, auxmap_L1 is a cache of auxmap_L2. The L2-L1
relationship is one of inclusion; iow L2 is not a victim cache.
There is extensive new sanity check code for these structures.
- Along with the auxmap changes are semi-fast cases in mc_LOADVn_slow
and mc_STOREVn_slow. These catch naturally aligned, word-size loads
which fall into addressible memory, and handle them directly rather
than in a byte-by-byte fashion.
- Fix longstanding error with alignment checks in
{new,die}_mem_stack_N. Previously, these checked the alignment of
the new SP value without taking the stack redzone size into account.
This is only safe if the redzone size is 8-aligned. The right thing
to do is check alignment after adding on the redzone size.
- Add a new mechanism which allows specification, on the command line,
of address ranges which memcheck is to 'ignore'. Meaning that it
regards all writes to those ranges as acceptable and all reads from
those ranges as acceptable and returning initialised data. This is
done without disturbing the existing finally-balanced bitmap
machinery. Instead, in mc_record_address_error, just ignore the
error if the address falls inside an ignored-range.
There is a new command-line flag --ignore-ranges= to specify
the address ranges. Currently up to 4 non-overlapping ranges may
be specified.
This kind of thing is useful if you want to do some strange thing
like map a high-performance network card into memory and can't be
bothered to tell memcheck about it through the official channels
(intercepting syscalls/ioctls and telling aspacem about them.)
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@6256 a5019735-40e9-0310-863c-91ae7b9d1cf9
1 file changed