[Qemu-devel] [PATCH v2 00/10] tb hash improvements

[Emilio G. Cota]

See v1 for context:
 https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg00587.html

All patches in v2 are checkpatch-clean, except 05 (checkpatch should
be ignored for this one) and 06, which I took unmodified (later patches
fix those warnings while doing other things, anyway).

Note that patch 01 has already been picked up by Paolo; I left it
here for completeness.

Another patch that is related to this series is the transition of
tb->flags to uint32_t; this has been sent as a separate patch since
it touches all targets. It shouldn't conflict with this patchset.

Changes from v1:
- Drop QEMU_CACHELINE, define QEMU_ALIGNED()
  + Remove excessive caution about Windows: it supports it.
  + define QHT_BUCKET_ALIGN as 64
- Add some reviewed-by tags from Alex.
- Drop POSIX spinlock wrapper; use the one pointed out by Paolo
  + Add a couple of fixes over this spinlock implementation:
    * define cpu_relax() for some architectures
    * Optimize spin_lock() for uncontended cases
- Add tb_hash_func5, a version of xxhash32 customized for tb-hash, so
  that the input values do not have to be contiguous in memory.
  + Drop xxhash.h, add only the customized version at exec/tb-hash-xx.h
- qht
  + use size_t for counts in qht
    * Drop some 2**32 size checks in there; it's not really a problem
      in practice.
  + s/__func/func__locked/
  + Test program: hash with tb_hash_func5

Thanks,

                Emilio