Commit Graph

13 Commits

Author SHA1 Message Date
Jason Evans
b683734b43 Implement BITMAP_INFO_INITIALIZER(nbits).
This allows static initialization of bitmap_info_t structures.
2016-05-13 10:27:48 -07:00
Jason Evans
245ae6036c Support --with-lg-page values larger than actual page size.
During over-allocation in preparation for creating aligned mappings,
allocate one more page than necessary if PAGE is the actual page size,
so that trimming still succeeds even if the system returns a mapping
that has less than PAGE alignment.  This allows compiling with e.g. 64
KiB "pages" on systems that actually use 4 KiB pages.

Note that for e.g. --with-lg-page=21, it is also necessary to increase
the chunk size (e.g. --with-malloc-conf=lg_chunk:22) so that there are
at least two "pages" per chunk.  In practice this isn't a particularly
compelling configuration because so much (unusable) virtual memory is
dedicated to chunk headers.
2016-04-11 02:35:00 -07:00
Jason Evans
2ee2f1ec57 Reduce differences between alternative bitmap implementations. 2016-04-06 10:38:47 -07:00
Jason Evans
4a8abbb400 Fix bitmap_sfu() regression.
Fix bitmap_sfu() to shift by LG_BITMAP_GROUP_NBITS rather than
hard-coded 6 when using linear (non-USE_TREE) bitmap search.  In
practice this affects only 64-bit systems for which sizeof(long) is not
8 (i.e. Windows), since USE_TREE is defined for 32-bit systems.

This regression was caused by b8823ab026
(Use linear scan for small bitmaps).

This resolves #368.
2016-04-06 10:32:06 -07:00
Jason Evans
20fad3430c Refactor some bitmap cpp logic. 2016-02-26 14:43:39 -08:00
Dave Watson
b8823ab026 Use linear scan for small bitmaps
For small bitmaps, a linear scan of the bitmap is slightly faster than
a tree search - bitmap_t is more compact, and there are fewer writes
since we don't have to propogate state transitions up the tree.
On x86_64 with the current settings, I'm seeing ~.5%-1% CPU improvement
in production canaries with this change.

The old tree code is left since 32bit sizes are much larger (and ffsl
smaller), and maybe the run sizes will change in the future.

This resolves #339.
2016-02-26 14:21:10 -08:00
Jason Evans
01ecdf32d6 Miscellaneous bitmap refactoring. 2016-02-26 14:21:10 -08:00
Jason Evans
9e1810ca9d Silence miscellaneous 64-to-32-bit data loss warnings. 2016-02-24 13:03:48 -08:00
Jason Evans
9f4ee6034c Refactor jemalloc_ffs*() into ffs_*().
Use appropriate versions to resolve 64-to-32-bit data loss warnings.
2016-02-24 13:03:48 -08:00
Jason Evans
551ebc4364 Convert to uniform style: cond == false --> !cond 2014-10-03 10:16:09 -07:00
Jason Evans
f97e5ac4ec Implement compile-time bitmap size computation. 2014-09-28 14:43:11 -07:00
Richard Diamond
9c3a10fdf6 Try to use __builtin_ffsl if ffsl is unavailable.
Some platforms (like those using Newlib) don't have ffs/ffsl.  This
commit adds a check to configure.ac for __builtin_ffsl if ffsl isn't
found.  __builtin_ffsl performs the same function as ffsl, and has the
added benefit of being available on any platform utilizing
Gcc-compatible compiler.

This change does not address the used of ffs in the MALLOCX_ARENA()
macro.
2014-06-02 07:44:50 -07:00
Jason Evans
7427525c28 Move repo contents in jemalloc/ to top level. 2011-03-31 20:36:17 -07:00