- #Berkeley upc memory fence drivers
- #Berkeley upc memory fence software
- #Berkeley upc memory fence code
Linker | /data/seismo82/avinash/Programs/openmpiinstall/bin/mpic | -Wunused-result -Wno-unused-parameter -Wno-address | large-function-growth=200000 -Wno-unused
#Berkeley upc memory fence software
| (C) 2015 Free Software Foundation, Inc.Ĭ compiler flags | -O3 -param max-inline-insns-single=35000 -param Runtime interface # | Runtime supports 3.0 -> 3.13: Translator uses 3.6 | segment_fast,os_linux,cpu_x86_64,cpu_64,cc_gnu,Ĭonfigure id | range Tue Feb 11 23:18: gnome-initial-setupīinary interface | 64-bit x86_64-unknown-linux-gnu | notrace,nostats,nodebugmalloc,nogasp,nothrille, | upc_atomics,pupc,upc_types,upc_castable,upc_nb,nodebug, | upc_trace_mask,upc_local_to_shared,upc_all_free, | upc_sem,upc_dump_shared,upc_trace_printf, | upc_memcpy_vis,upc_ptradd,upc_thread_distance,upc_tick, | gasnet,upc_collective,upc_io,upc_memcpy_async, | 019.4.0.cgi' '-with-sptr-packed-bits=20,9,35'Ĭonfigure features | trans_bupc,pragma_upc_code,driver_upcc,runtime_upcr, Pthreads support | available (if used, default is 2 pthreads per process) This is upcc (the Berkeley Unified Parallel C compiler), v. The UPC build was compiled using flags -with-sptr-packed-bits=20,9,35 that allows up to 2^35 = 32 GB of shared memory per thread.ĮDIT1: Following is the output of the command upcc -version jointinvsurf5_cajoint_compile]$ upcc -version I cannot over-ride it even with a the shared-heap flag where I am clearly asking for 5 GB per thread. I don't understand why the Total shared memory limit is 128 GB which is half of the total physical memory present. NOTICE: We recommend linking the debug version of GASNet to assist you in resolving this application issue. NOTICE: Before reporting bugs, run with GASNET_BACKTRACE=1 in the environment to generate a backtrace. Upc_alloc unable to service request from thread 245248 more bytes Total shared memory limit: 2515 MB per-thread, 128281 MB total Global shared memory in use: 0 MB per-thread, 1 MB total Local shared memory in use: 1594 MB per-thread, 81340 MB total The following should work because 51 x 5 = 255 GB available (2515 MB) on node 0 (range): using 2515 MB per thread instead
#Berkeley upc memory fence code
However the code fails to run because it cannot find enough memory. use of the volatile keyword in C).I am trying to run a Berkeley UPC code on a computer with 64 cores and 256 GB RAM. You need to take separate measures to stop the compiler reordering your instructions if that may cause undesirable behaviour (e.g. The CPU reordering is different from compiler optimisations - although the artefacts can be similar.
#Berkeley upc memory fence drivers
Use of memory barriers requires a careful study of the hardware architecture and more commonly found in device drivers than application code. In higher level languages we are used to dealing with mutexes and semaphores - these may well be implemented using memory fences at the low level and explicit use of memory barriers are not necessary. Note memory fences are a hardware concept. For example a 'full fence' means all read/writes before the fence are comitted before those after the fence. However for multiple threads or environments with volatile memory (memory mapped I/O for example) this can lead to unpredictable behavior.Ī memory fence/barrier is a class of instructions that mean memory read/writes occur in the order you expect. Because the hardware enforces instructions integrity you never notice this in a single thread of execution. For performance gains modern CPUs often execute instructions out of order to make maximum use of the available silicon (including memory read/writes).
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