Details:
- Implemented a sophisticated data structure and set of APIs that track
the small blocks of memory (around 80-100 bytes each) used when
creating nodes for control and thread trees (cntl_t and thrinfo_t) as
well as thread communicators (thrcomm_t). The purpose of the small
block allocator, or sba, is to allow the library to transition into a
runtime state in which it does not perform any calls to malloc() or
free() during normal execution of level-3 operations, regardless of
the threading environment (potentially multiple application threads
as well as multiple BLIS threads). The functionality relies on a new
data structure, apool_t, which is (roughly speaking) a pool of
arrays, where each array element is a pool of small blocks. The outer
pool, which is protected by a mutex, provides separate arrays for each
application thread while the arrays each handle multiple BLIS threads
for any given application thread. The design minimizes the potential
for lock contention, as only concurrent application threads would
need to fight for the apool_t lock, and only if they happen to begin
their level-3 operations at precisely the same time. Thanks to Kiran
Varaganti and AMD for requesting this feature.
- Added a configure option to disable the sba pools, which are enabled
by default; renamed the --[dis|en]able-packbuf-pools option to
--[dis|en]able-pba-pools; and rewrote the --help text associated with
this new option and consolidated it with the --help text for the
option associated with the sba (--[dis|en]able-sba-pools).
- Moved the membrk field from the cntx_t to the rntm_t. We now pass in
a rntm_t* to the bli_membrk_acquire() and _release() APIs, just as we
do for bli_sba_acquire() and _release().
- Replaced all calls to bli_malloc_intl() and bli_free_intl() that are
used for small blocks with calls to bli_sba_acquire(), which takes a
rntm (in addition to the bytes requested), and bli_sba_release().
These latter two functions reduce to the former two when the sba pools
are disabled at configure-time.
- Added rntm_t* arguments to various cntl_t and thrinfo_t functions, as
required by the new usage of bli_sba_acquire() and _release().
- Moved the freeing of "old" blocks (those allocated prior to a change
in the block_size) from bli_membrk_acquire_m() to the implementation
of the pool_t checkout function.
- Miscellaneous improvements to the pool_t API.
- Added a block_size field to the pblk_t.
- Harmonized the way that the trsm_ukr testsuite module performs packing
relative to that of gemmtrsm_ukr, in part to avoid the need to create
a packm control tree node, which now requires a rntm_t that has been
initialized with an sba and membrk.
- Re-enable explicit call bli_finalize() in testsuite so that users who
run the testsuite with memory tracing enabled can check for memory
leaks.
- Manually imported the compact/minor changes from 61441b24 that cause
the rntm to be copied locally when it is passed in via one of the
expert APIs.
- Reordered parameters to various bli_thrcomm_*() functions so that the
thrcomm_t* to the comm being modified is last, not first.
- Added more descriptive tracing for allocating/freeing small blocks and
formalized via a new configure option: --[dis|en]able-mem-tracing.
- Moved some unused scalm code and headers into frame/1m/other.
- Whitespace changes to bli_pthread.c.
- Regenerated build/libblis-symbols.def.
Details:
- Removed explicit reference to The University of Texas at Austin in the
third clause of the license comment blocks of all relevant files and
replaced it with a more all-encompassing "copyright holder(s)".
- Removed duplicate words ("derived") from a few kernels' license
comment blocks.
- Homogenized license comment block in kernels/zen/3/bli_gemm_small.c
with format of all other comment blocks.
Details:
- Define a dummy bli_l3_thread_entry() function when multithreading is
disabled altogether, or enabled via OpenMP. This function was
originally necessary when multithreading is enabled via pthreads.
By defining the function no matter the threading options given, it is
less likely that an AppVeyor Windows build will complain due to a
missing symbol in the DLL. (To be clear: AppVeyor was working fine
before, but a problem may have arisen if it were switched to an
OpenMP build.)
- Removed the prototype for bli_l3_thread_entry() from
bli_thrcomm_pthreads.c and placed it in bli_thrcomm.h.
- Regenerated the symbols list file build/libblis-symbols.def.
Details:
- Removed four trailing spaces after "BLIS" that occurs in most files'
commented-out license headers.
- Added UT copyright lines to some files. (These files previously had
only AMD copyright lines but were contributed to by both UT and AMD.)
- In some files' copyright lines, expanded 'The University of Texas' to
'The University of Texas at Austin'.
- Fixed various typos/misspellings in some license headers.
Details:
- Reimplemented several sets of get/set-style preprocessor macros with
static functions, including those in the following frame/base headers:
auxinfo, cntl, mbool, mem, membrk, opid, and pool. A few headers in
frame/thread were touched as well: mutex_*, thrcomm, and thrinfo.
Details:
- Updated the non-tree openmp and pthreads barriers defined in
bli_thrcomm_openmp.c and bli_thrcomm_pthreads.c to instead call a common
implementation in bli_thrcomm.c, bli_thrcomm_barrier_atomic(). This new
implementation goes through the same motions as the previous codes, but
protects its loads and increments with GNU atomic built-ins. These atomic
statements take memory ordering parameters that allow us to specify just
enough constraints for the barrier to work as intended on weakly-ordered
hardware. The prior implementation was only guaranteed to work on systems
with strongly- ordered memory. (Thanks to Devin Matthews for suggesting
this change and his crash-course in atomics and memory ordering.)
- Removed 'volatile' from structs' barrier field declarations in
bli_thrcomm_*.h.
- Updated bli_thrcomm_pthread.? files to use renamed struct barrier fields
consistent with that of the _openmp.? files.
- Updated other bli_thrcomm_* files to rename "communicator" variables to
simply "comm".
Details:
- Implemented Ricardo Magana's distributed thread info/communicator
management. Rather that fully construct the thrinfo_t structures, from
root to leaf, prior to spawning threads, the threads individually
construct their thrinfo_t trees (or, chains), and do so incrementally,
as needed, reusing the same structure nodes during subsequent blocked
variant iterations. This required moving the initial creation of the
thrinfo_t structure (now, the root nodes) from the _front() functions
to the bli_l3_thread_decorator(). The incremental "growing" of the tree
is performed in the internal back-end (ie: _int()) function, and so
mostly invisible. Also, the incremental growth of the thrinfo_t tree is
done as a function of the current and parent control tree nodes (as well
as the parent thrinfo_t node), further reinforcing the parallel
relationship between the two data structures.
- Removed the "inner" communicator from thrinfo_t structure definition,
as well as its id. Changed all APIs accordingly. Renamed
bli_thrinfo_needs_free_comms() to bli_thrinfo_needs_free_comm().
- Defined bli_l3_thrinfo_print_paths(), which prints the information
in an array of thrinfo_t* structure pointers. (Used only as a
debugging/verification tool.)
- Deprecated the following thrinfo_t creation functions:
bli_packm_thrinfo_create()
bli_l3_thrinfo_create()
because they are no longer used. bli_thrinfo_create() is now called
directly when creating thrinfo_t nodes.
Details:
- Reorganized code and renamed files defining APIs related to multithreading.
All code that is not specific to a particular operation is now located in a
new directory: frame/thread. Code is now organized, roughly, by the
namespace to which it belongs (see below).
- Consolidated all operation-specific *_thrinfo_t object types into a single
thrinfo_t object type. Operation-specific level-3 *_thrinfo_t APIs were
also consolidated, leaving bli_l3_thrinfo_*() and bli_packm_thrinfo_*()
functions (aside from a few general purpose bli_thrinfo_*() functions).
- Renamed thread_comm_t object type to thrcomm_t.
- Renamed many of the routines and functions (and macros) for multithreading.
We now have the following API namespaces:
- bli_thrinfo_*(): functions related to thrinfo_t objects
- bli_thrcomm_*(): functions related to thrcomm_t objects.
- bli_thread_*(): general-purpose functions, such as initialization,
finalization, and computing ranges. (For now, some macros, such as
bli_thread_[io]broadcast() and bli_thread_[io]barrier() use the
bli_thread_ namespace prefix, even though bli_thrinfo_ may be more
appropriate.)
- Renamed thread-related macros so that they use a bli_ prefix.
- Renamed control tree-related macros so that they use a bli_ prefix (to be
consistent with the thread-related macros that were also renamed).
- Removed #undef BLIS_SIMD_ALIGN_SIZE from dunnington's bli_kernel.h. This
#undef was a temporary fix to some macro defaults which were being applied
in the wrong order, which was recently fixed.
