as opposed to the valgrind code proper. In particular, make sure that
-mpreferred-stack-boundary=2 does not get used for the preload shared
objects, since that can cause the stack to become misaligned and leads
to segfaults. Modified version of a patch from Matthias Schwarzott
(zzam@gentoo.org). Fixes#324050.
Also, fix the configure check in configure.ac for
-mpreferred-stack-boundary=2 so that it checks whether this is
allowable for 32-bit code generation even on 64-bit (x86) hosts. This
check was wrong before now and led to 32-bit builds on 64-bit hosts
generating poorer code for speed critical helper functions (eg
helperc_LOADV32le) than on 32-bit builds on 32-bit hosts.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14471
is a heap profiler that is complementary to Massif. DHAT tracks heap
allocations, and connects which memory accesses are to which blocks.
It can find the following information:
* total allocation and max liveness
* average block lifetime (# instructions between allocation and
freeing)
* average number of reads and writes to each byte in the block
("access ratios")
* average of longest interval of non-access to a block, also
measured in instructions
* which fields of blocks are used a lot, and which aren't
(hot-field profiling)
Using these stats it is possible to identify allocation points with
the following characteristics:
* potential process-lifetime leaks (blocks allocated by the point just
accumulate, and are freed only at the end of the run)
* excessive turnover: points which chew through a lot of heap, even if
it is not held onto for very long
* excessively transient: points which allocate very short lived blocks
* useless or underused allocations: blocks which are allocated but not
completely filled in, or are filled in but not subsequently read.
* blocks which see extended periods of inactivity. Could these
perhaps be allocated later or freed sooner?
* blocks with inefficient layout (hot fields spread out over
multiple cache lines), or with alignment holes
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11431
