This patch adds the affinity format functionality introduced in OpenMP 5.0.
This patch adds: Two new environment variables:
OMP_DISPLAY_AFFINITY=TRUE|FALSE
OMP_AFFINITY_FORMAT=<string>
and Four new API:
1) omp_set_affinity_format()
2) omp_get_affinity_format()
3) omp_display_affinity()
4) omp_capture_affinity()
The affinity format functionality has two ICV's associated with it:
affinity-display-var (bool) and affinity-format-var (string).
The affinity-display-var enables/disables the functionality through the
envirable OMP_DISPLAY_AFFINITY. The affinity-format-var is a formatted
string with the special field types beginning with a '%' character
similar to printf
For example, the affinity-format-var could be:
"OMP: host:%H pid:%P OStid:%i num_threads:%N thread_num:%n affinity:{%A}"
The affinity-format-var is displayed by every thread implicitly at the beginning
of a parallel region when any thread's affinity has changed (including a brand
new thread being spawned), or explicitly using the omp_display_affinity() API.
The omp_capture_affinity() function can capture the affinity-format-var in a
char buffer. And omp_set|get_affinity_format() allow the user to set|get the
affinity-format-var explicitly at runtime. omp_capture_affinity() and
omp_get_affinity_format() both return the number of characters needed to hold
the entire string it tried to make (not including NULL character). If not
enough buffer space is available,
both these functions truncate their output.
Differential Revision: https://reviews.llvm.org/D55148
llvm-svn: 349089
Balanced affinity only updated the thread's affinity with the operating system.
This change also has the thread's private mask reflect that change as well so
that any API that probes the thread's affinity mask will report the correct
mask value.
Differential Revision: https://reviews.llvm.org/D52379
llvm-svn: 343142
This patch cleans up unused functions, variables, sign compare issues, and
addresses some -Warning flags which are now enabled including -Wcast-qual.
Not all the warning flags in LibompHandleFlags.cmake are enabled, but some
are with this patch.
Some __kmp_gtid_from_* macros in kmp.h are switched to static inline functions
which allows us to remove the awkward definition of KMP_DEBUG_ASSERT() and
KMP_ASSERT() macros which used the comma operator. This had to be done for the
innumerable -Wunused-value warnings related to KMP_DEBUG_ASSERT()
Differential Revision: https://reviews.llvm.org/D49105
llvm-svn: 339393
This patch introduces the logic implementing hierarchical scheduling.
First and foremost, hierarchical scheduling is off by default
To enable, use -DLIBOMP_USE_HIER_SCHED=On during CMake's configure stage.
This work is based off if the IWOMP paper:
"Workstealing and Nested Parallelism in SMP Systems"
Hierarchical scheduling is the layering of OpenMP schedules for different layers
of the memory hierarchy. One can have multiple layers between the threads and
the global iterations space. The threads will go up the hierarchy to grab
iterations, using possibly a different schedule & chunk for each layer.
[ Global iteration space (0-999) ]
(use static)
[ L1 | L1 | L1 | L1 ]
(use dynamic,1)
[ T0 T1 | T2 T3 | T4 T5 | T6 T7 ]
In the example shown above, there are 8 threads and 4 L1 caches begin targeted.
If the topology indicates that there are two threads per core, then two
consecutive threads will share the data of one L1 cache unit. This example
would have the iteration space (0-999) split statically across the four L1
caches (so the first L1 would get (0-249), the second would get (250-499), etc).
Then the threads will use a dynamic,1 schedule to grab iterations from the L1
cache units. There are currently four supported layers: L1, L2, L3, NUMA
OMP_SCHEDULE can now read a hierarchical schedule with this syntax:
OMP_SCHEDULE='EXPERIMENTAL LAYER,SCHED[,CHUNK][:LAYER,SCHED[,CHUNK]...]:SCHED,CHUNK
And OMP_SCHEDULE can still read the normal SCHED,CHUNK syntax from before
I've kept most of the hierarchical scheduling logic inside kmp_dispatch_hier.h
to try to keep it separate from the rest of the code.
Differential Revision: https://reviews.llvm.org/D47962
llvm-svn: 336571
Currently, the affinity API reports garbage for the initial place list and any
thread's place lists when using KMP_AFFINITY=none|compact|scatter.
This patch does two things:
for KMP_AFFINITY=none, Creates a one entry table for the places, this way, the
initial place list is just a single place with all the proc ids in it. We also
set the initial place of any thread to 0 instead of KMP_PLACE_ALL so that the
thread reports that single place (place 0) instead of garbage (-1) when using
the affinity API.
When non-OMP_PROC_BIND affinity is used
(including KMP_AFFINITY=compact|scatter), a thread's place list is populated
correctly. We assume that each thread is assigned to a single place. This is
implemented in two of the affinity API functions
Differential Revision: https://reviews.llvm.org/D45527
llvm-svn: 330283
There are two /proc/cpuinfo layots in use for AArch64: old and new.
The old one has all 'processor : n' lines in one section, hence
checking for duplications does not make sense.
Differential Revision: https://reviews.llvm.org/D41000
llvm-svn: 320593
To make thread affinity work according to the OpenMP spec, the
runtime needs information about the hardware topology. On Linux
the default way is to parse /proc/cpuinfo which contains this
information for x86 machines but (at least) not for AArch64 and
Power architectures.
Fortunately, there is a different code path which is able to get
that data from sysfs. The needed patch has landed in 2006 for
Linux 2.6.16 which is safe to assume nowadays (even RHEL 5 had
a kernel version derived from 2.6.18, and we are now at RHEL 7!).
Differential Revision: https://reviews.llvm.org/D40357
llvm-svn: 320151
Redundant extra verbose output of binding to full mask in case
affinity=balanced or OMP_PLACES=<any> or OMP_PROC_BIND=<any>
Differential Revision: https://reviews.llvm.org/D40624
llvm-svn: 319960
Added two warnings:
1) Before building the topology map check if tiles are requested but the
topo method is not hwloc;
2) After building the topology map check if tiles are requested but not
detected by the library.
Patch by Olga Malysheva
Differential Revision: https://reviews.llvm.org/D40340
llvm-svn: 319374
Removes semicolons after if {} blocks, function definitions, etc.
I was able to apply the large OMPT patch cleanly on top of this one
with no conflicts.
llvm-svn: 314340
Minor code cleanup of Klocwork issues. Fatal messages are given no return
attribute. Define and use KMP_NORETURN to work for multiple C++ versions.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D37275
llvm-svn: 312538
Changes are: got all atomics to accept volatile pointers that allowed
to simplify many type conversions. Windows specific code fixed correspondingly.
Differential Revision: https://reviews.llvm.org/D35417
llvm-svn: 308164
Changes are: replaced C-style casts with cons_cast and reinterpret_cast;
type of several counters changed to signed; type of parameters of 32-bit and
64-bit AND and OR intrinsics changes to unsigned; changed files formatted
using clang-format version 3.8.1.
Differential Revision: https://reviews.llvm.org/D34759
llvm-svn: 307020
Some code was restructured to move it under KMP_DEBUG. The rest is
formatting changes to fix some things broken by clang-format
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D33744
llvm-svn: 304438
With these settings, the create_hwloc_map() method was being called causing an
assert(). After some consideration, it was determined that disabling affinity
explicitly should just disable hwloc as well. i.e., KMP_AFFINITY overrides
KMP_TOPOLOGY_METHOD. This lets the user know that the Hwloc mechanism is being
ignored when KMP_AFFINITY=disabled.
Differential Revision: https://reviews.llvm.org/D33208
llvm-svn: 304344
An assert() was being tripped when KMP_AFFINITY=respect + Multiple Processor
Groups. Let __kmp_affinity_create_proc_group_map() function be able to create
address2os object which contains a single group by deleting restriction that
process affinity mask must span multiple groups.
llvm-svn: 303101
This patch contains the clang-format and cleanup of the entire code base. Some
of clang-formats changes made the code look worse in places. A best effort was
made to resolve the bulk of these problems, but many remain. Most of the
problems were mangling line-breaks and tabbing of comments.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D32659
llvm-svn: 302929
Older Hwloc libraries (< 1.10.0) don't offer the HWLOC_OBJ_NUMANODE nor
HWLOC_OBJ_PACKAGE types. Instead they are named HWLOC_OBJ_NODE and
HWLOC_OBJ_SOCKET instead. This patch just defines the newer names based on
the older names when using an older Hwloc.
Differential Revision: https://reviews.llvm.org/D32496
llvm-svn: 301349
Affinity initialization code expects __kmp_affinity_type has the value
affinity_default by default, but the cleanup code does not properly set the
value back to affinity_default. This may introduce some issues when multiple
roots are trying to initialize/uninitialize the runtime successively.
Patch by Hansang Bae
Differential Revision: https://reviews.llvm.org/D31012
llvm-svn: 298313
Clang 4.0 trunk warns:
warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses]
This points to a potential bug if the code really wants to check if the single
bit is not set: If for example (buf.edx >> 9) = 2 (has any bit set except the
least significant one), 'logical not' will return 0 which stays 0 after the
'bitwise and'.
To do this correctly we first need to evaluate the 'bitwise and'. In that case
it returns 2 & 1 = 0 which after the 'logical not' evaluates to 1.
Differential Revision: https://reviews.llvm.org/D28599
llvm-svn: 291764
This set of changes enables the affinity interface (Either the preexisting
native operating system or HWLOC) to be dynamically set at runtime
initialization. The point of this change is that we were seeing performance
degradations when using HWLOC. This allows the user to use the old affinity
mechanisms which on large machines (>64 cores) makes a large difference in
initialization time.
These changes mostly move affinity code under a small class hierarchy:
KMPAffinity
class Mask {}
KMPNativeAffinity : public KMPAffinity
class Mask : public KMPAffinity::Mask
KMPHwlocAffinity
class Mask : public KMPAffinity::Mask
Since all interface functions (for both affinity and the mask implementation)
are virtual, the implementation can be chosen at runtime initialization.
Differential Revision: https://reviews.llvm.org/D26356
llvm-svn: 286890
Rather than checking KMP_CPU_SETSIZE, which doesn't exist when using Hwloc, we
use the get_max_proc() function which can vary based on the operating system.
For example on Windows with multiple processor groups, it might be the case that
the highest bit possible in the bitmask is not equal to the number of hardware
threads on the machine but something higher than that.
Differential Revision: https://reviews.llvm.org/D24206
llvm-svn: 281245
When affinity isn't supported, __kmp_affinity_compact doesn't exist. The
problem is that in kmp_affinity.h there is a function which uses it without the
proper KMP_AFFINITY_SUPPORTED guard around it. The compiler was smart enough to
ignore it and the function __kmp_affinity_cmp_Address_child_num which relies on
it, but I think it is cleaner to have it under the proper guard. Since the
function is only used in the kmp_affinity.cpp file and there aren't any plans to
have it elsewhere. I have moved it there.
llvm-svn: 280542
This patch enables balanced affinity on machines that do not have
hardware threads and have cores clustered into packages. In facts,
balacing algorithm could be generalized for any arrangement with
at least two levels of hierarchy (depth > 1).
Differential Revision: https://reviews.llvm.org/D22365
llvm-svn: 277212
A couple improvements:
1) Add ability to limit fullMask size when KMP_HW_SUBSET limits resources.
2) Make KMP_HW_SUBSET work for affinity_none, and only limit fullMask in this case.
Patch by Andrey Churbanov.
Differential Revision: http://reviews.llvm.org/D21528
llvm-svn: 273278
Change hwloc discovery algorithm to print topology for only accessible
resources, and report uniformity correspondingly, similar to what other topology
discovery algorithms do. Fixes minor inconsistency in total topology reported
and resources used for threads binding in case hwloc used.
Patch by Andrey Churbanov.
Differential Revision: http://reviews.llvm.org/D21389
llvm-svn: 272952
Cleanup: fixed missing memory cleanup in couple of corner cases. Fixes possible
memory leak in some corner cases
Patch by Andrey Churbanov
Differential Revision: http://reviews.llvm.org/D21355
llvm-svn: 272946
Deprecate KMP_PLACE_THREADS and rename it to KMP_HW_SUBSET due to confusion
about its purpose and function among users. KMP_HW_SUBSET is an environment
variable which allows users to easily pick a subset of the hardware topology to
use. e.g., KMP_HW_SUBSET=30c,2t means use 30 cores, 2 threads per core.
Patch by Andrey Churbanov
Differential Revision: http://reviews.llvm.org/D21340
llvm-svn: 272937
Remove static specifier from var fullMask and remove kmp_get_fullMask() routine.
When iterating through procs in a mask, always check if proc is in fullMask
(this check was missing in a few places).
Patch by Brian Bliss.
Differential Revision: http://reviews.llvm.org/D21300
llvm-svn: 272589
These changes remove the hwloc_topology_ignore_type function which doesn't exist
in the hwloc 2.0 API. In the existing code, the topology extracted from hwloc
has the cache levels stripped out and then assumes the final stripped topology
follows the typical three-level topology: packages -> cores -> HW threads.
But the code is doing unclean manipulations to determine at what level those
resources are located and also assumes too much about what hwloc is detecting
(there could be intermediate levels in between socket and core for instance).
This new way of extracting the topology doesn't strip out any hardware objects
that hwloc detects. It does not assume the three level topology, and instead
searches for the relevant three levels within the topology for each bit of
information using hwloc interface functions. i.e., the three level topology
subset that our affinity code is interested in is extracted from the hwloc
topology tree directly.
For example, the new __kmp_hwloc_get_nobjs_under_obj function gives the user the
number of cores under a socket reliably without worrying if there are unexpected
objects between the socket object and core object in the hwloc topology
structure. Also, now that all topology information is kept, there are also
possibilities of using the caches/numa nodes to determine more sophisticated
affinity settings in the future.
There is also some cleanup code added for the destruction of the
__kmp_hwloc_topology object.
Differential Revision: http://reviews.llvm.org/D21195
llvm-svn: 272565
This debug sections's functionality can be replicated using the environment
variable KMP_TOPOLOGY_METHOD with different values and KMP_AFFINITY=verbose
llvm-svn: 267472
This change has the hwloc_bitmap_list_snprintf() function use the entire buffer
to print the mask. There is no need to shorten the buffer length by 7. It only
needs to be shortened by one byte.
llvm-svn: 267470
This new API, int kmp_set_thread_affinity_mask_initial(), is available for use
by other parallel runtime libraries inside a possibly OpenMP-registered thread.
This entry point restores the current thread's affinity mask to the affinity
mask of the application when it first began. If -1 is returned it can be assumed
that either the thread hasn't called affinity initialization or that the thread
isn't registered with the OpenMP library. If 0 is returned then, then the call
was successful. Any return value greater than zero indicates an error occurred
when setting affinity.
Differential Revision: http://reviews.llvm.org/D15867
llvm-svn: 257489
These changes allow libhwloc to be used as the topology discovery/affinity
mechanism for libomp. It is supported on Unices. The code additions:
* Canonicalize KMP_CPU_* interface macros so bitmask operations are
implementation independent and work with both hwloc bitmaps and libomp
bitmaps. So there are new KMP_CPU_ALLOC_* and KMP_CPU_ITERATE() macros and
the like. These are all in kmp.h and appropriately placed.
* Hwloc topology discovery code in kmp_affinity.cpp. This uses the hwloc
interface to create a libomp address2os object which the rest of libomp knows
how to handle already.
* To build, use -DLIBOMP_USE_HWLOC=on and
-DLIBOMP_HWLOC_INSTALL_DIR=/path/to/install/dir [default /usr/local]. If CMake
can't find the library or hwloc.h, then it will tell you and exit.
Differential Revision: http://reviews.llvm.org/D13991
llvm-svn: 254320
These changes include:
1) Machine hierarchy now uses the base_num_threads field to indicate the
maximum number of threads the current hierarchy can handle without a resize.
2) In __kmp_get_hierarchy, we need to get depth after any potential resize
is done.
3) Cleanup of hierarchy resize code to support 1 above.
Differential Revision: http://reviews.llvm.org/D14455
llvm-svn: 252475
Added (optional) sockets to the syntax of the KMP_PLACE_THREADS environment variable.
Some limitations:
* The number of sockets and then optional offset should be specified first (before other parameters).
* The letter designation is mandatory for sockets and then for other parameters.
* If number of cores is specified first, then the number of sockets is defaulted to all sockets on the machine; also, the old syntax is partially supported if sockets are skipped.
* If number of threads per core is specified first, then the number of sockets and cores per socket are defaulted to all sockets and all cores per socket respectively.
* The number of cores per socket cannot be specified before sockets or after threads per core.
* The number of threads per core can be specified before or after core-offset (old syntax required it to be before core-offset);
* Parameters delimiter can be: empty, comma, lower-case x;
* Spaces are allowed around numbers, around letters, around delimiter.
Approximate shorthand specification:
KMP_PLACE_THREADS="[num_sockets(S|s)[[delim]offset(O|o)][delim]][num_cores_per_socket(C|c)[[delim]offset(O|o)][delim]][num_threads_per_core(T|t)]"
Differential Revision: http://reviews.llvm.org/D13175
llvm-svn: 249708
This patch adjusts the buffer size when reducing the buffer used for printing.
This solves the memory corruption in Windows debug library, and potential
memory corruption in other builds.
llvm-svn: 248588
This is a follow up to the hierarchy cleanup patch.
Added some clarifying comments to hierarchy_info.
Fixed a bug with the depth field not being updated cleanly during a resize.
Fixed resize to first check capacity as determined by maxLevels before actually doing the full resize.
Differential Revision: http://reviews.llvm.org/D12562
llvm-svn: 247333
Some of this is improvement to code suggested by Hal Finkel. Four changes here:
1.Cleanup of hierarchy code to handle all hierarchy cases whether affinity is available or not
2.Separated this and other classes and common functions out to a header file
3.Added a destructor-like fini function for the hierarchy (and call in __kmp_cleanup)
4.Remove some redundant code that is hopefully no longer needed
Differential Revision: http://reviews.llvm.org/D12449
llvm-svn: 247326
This patch fixes a bug when eliminating layers in the machine topology (namely
cores, and threads). Before this patch, if a user specifies using only one
thread per socket, then affinity is not set properly due to bad topology
pruning.
Differential Revision: http://reviews.llvm.org/D11158
llvm-svn: 245966
This fix allows the machine hierarchy to be expanded in case it needs to handle
more threads. It adds a resize function to accomplish this.
Differential Revision: http://reviews.llvm.org/D9900
llvm-svn: 240292
Jonathan Peyton