[Openmp-commits] [openmp] r219214 - I apologise in advance for the size of this check-in. At Intel we do
hfinkel at anl.gov
Tue Oct 7 14:45:16 PDT 2014
Some comments inline...
----- Original Message -----
> From: "Jim Cownie" <james.h.cownie at intel.com>
> To: openmp-commits at cs.uiuc.edu
> Sent: Tuesday, October 7, 2014 11:25:52 AM
> Subject: [Openmp-commits] [openmp] r219214 - I apologise in advance for the size of this check-in. At Intel we do
> Author: jimcownie
> Date: Tue Oct 7 11:25:50 2014
> New Revision: 219214
> URL: http://llvm.org/viewvc/llvm-project?rev=219214&view=rev
> I apologise in advance for the size of this check-in. At Intel we do
> understand that this is not friendly,
The remailer creates the subject line of the e-mail messages from the first line of the commit message. As a result, this first line should be a hyper-short summary of the change (in this case, it ended up being, " I apologise in advance for the size of this check-in. At Intel we do").
> and are working to change our
> internal code-development to make it easier to make development
> features available more frequently and in finer (more functional)
> chunks. Unfortunately we haven't got that in place yet, and unpicking
> this into multiple separate check-ins would be non-trivial, so please
> bear with me on this one. We should be better in the future.
> Apologies over, what do we have here?
> GGC 4.9 compatibility
> * We have implemented the new entrypoints used by code compiled by
> 4.9 to implement the same functionality in gcc 4.8. Therefore code
> compiled with gcc 4.9 that used to work will continue to do so.
> However, there are some other new entrypoints (associated with task
> cancellation) which are not implemented. Therefore user code compiled
> by gcc 4.9 that uses these new features will not link against the
> runtime. (It remains unclear how to handle those entrypoints, since
> the GCC interface has potentially unpleasant performance implications
> for join barriers even when cancellation is not used)
> --- new parallel entry points ---
> new entry points that aren't OpenMP 4.0 related
> These are implemented fully :-
> --- cancellation entry points ---
> Currently, these only give a runtime error if OMP_CANCELLATION is
> because our plain barriers don't check for cancellation while waiting
> --- taskgroup entry points ---
> These are implemented fully.
> --- target entry points ---
> These are empty (as they are in libgomp)
> Improvements in Barriers and Fork/Join
> * Barrier and fork/join code is now in its own file (which makes it
> easier to understand and modify).
> * Wait/release code is now templated and in its own file;
> suspend/resume code is also templated
> * There's a new, hierarchical, barrier, which exploits the
> cache-hierarchy of the Intel(r) Xeon Phi(tm) coprocessor to improve
> fork/join and barrier performance.
> ***BEWARE*** the new source files have *not* been added to the legacy
> Cmake build system. If you want to use that fixes wil be required.
> Statistics Collection Code
> * New code has been added to collect application statistics (if this
> is enabled at library compile time; by default it is not). The
> statistics code itself is generally useful, the lightweight timing
> code uses the X86 rdtsc instruction, so will require changes for
When building with Clang, we could use __builtin_readcyclecounter() and get automatic portability (perhaps).
> The intent of this code is not for users to tune their codes but
> 1) For timing code-paths inside the runtime
> 2) For gathering general properties of OpenMP codes to focus
> on which OpenMP features are most used.
> Nested Hot Teams
> * The runtime now maintains more state to reduce the overhead of
> creating and destroying inner parallel teams. This improves the
> performance of code that repeatedly uses nested parallelism with the
> same resource allocation. Set the new KMP_HOT_TEAMS_MAX_LEVEL
> envirable to a depth to enable this (and, of course, OMP_NESTED=true
> to enable nested parallelism at all).
> Improved Intel(r) VTune(Tm) Amplifier support
> * The runtime provides additional information to Vtune via the
> itt_notify interface to allow it to display better OpenMP specific
> analyses of load-imbalance.
> Support for OpenMP Composite Statements
> * Implement new entrypoints required by some of the OpenMP 4.1
> composite statements.
> Improved ifdefs
> * More separation of concepts ("Does this platform do X?") from
> platforms ("Are we compiling for platform Y?"), which should simplify
> future porting.
> ScaleMP* contribution
> Stack padding to improve the performance in their environment where
> cross-node coherency is managed at the page level.
> Redesign of wait and release code
> The code is simplified and performance improved.
> Bug Fixes
> *Fixes for Windows multiple processor groups.
> *Fix Fortran module build on Linux: offload attribute added.
> *Fix entry names for distribute-parallel-loop construct to be
> consistent with the compiler codegen.
> *Fix an inconsistent error message for KMP_PLACE_THREADS
> environment variable.
> openmp/trunk/runtime/tools/make-fat-binaries.pl (with props)
> Modified: openmp/trunk/CREDITS.txt
> --- openmp/trunk/CREDITS.txt (original)
> +++ openmp/trunk/CREDITS.txt Tue Oct 7 11:25:50 2014
> @@ -9,6 +9,7 @@ beautification by scripts. The fields a
> N: Carlo Bertolli
> +W: http://ibm.com
> D: IBM contributor to PowerPC support in CMake files and elsewhere.
> N: Sunita Chandrasekaran
> @@ -28,6 +29,11 @@ D: Created the runtime.
> N: Matthias Muller
> D: Contributor to testsuite from OpenUH
> +N: Tal Nevo
> +E: tal at scalemp.com
> +D: ScaleMP contributor to improve runtime performance there.
> +W: http://scalemp.com
> N: Pavel Neytchev
> D: Contributor to testsuite from OpenUH
> Modified: openmp/trunk/LICENSE.txt
> --- openmp/trunk/LICENSE.txt (original)
> +++ openmp/trunk/LICENSE.txt Tue Oct 7 11:25:50 2014
> @@ -14,7 +14,7 @@ software contained in this directory tre
> University of Illinois/NCSA
> Open Source License
> -Copyright (c) 1997-2013 Intel Corporation
> +Copyright (c) 1997-2014 Intel Corporation
These things, and the license headers, should really be committed separately. There are several different ways to separate a patch file into separate commits (and at least several of us here who have experience doing surgery on patches). Feel free to ask for advice (might as well do it on the dev list: it is a common problem), and you shall receive it.
> All rights reserved.
> @@ -51,7 +51,7 @@ SOFTWARE.
> Openmp-commits mailing list
> Openmp-commits at dcs-maillist2.engr.illinois.edu
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory
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