Haswell Transactional Memory read/write-set information

Recently, Intel release haswell machines which support hardware transactional memory called transactional synchronization extension(TSX).

As Intel manual said, Speculative memory operations, write-set and read-set, are buffered in L1 cache and L2 cache each. (not exactly)

Then, Can I track transactional memory operations and get information like address, and values of read/write-set?

I have a problem with igzip

I am studying about compression algorithm and software.
I have question about igzip. I download igzip library in intel homepage.
But I don`t know how to make wrapper.
Can you send me 'example of wrapper' or 'example code' or 'manual'?
I read homepage and saw a simple application.
I don`t know how to input target file for compression and to output compression file
and how to decompression?
Do I make code about 'fast_lz and init_stream' function by myself?
Plz help me.
thank you

PCM reporting lower than expected memory read counts

I have a piece of code on which I'm running PCM (Performance Counter Monitor). It is essentially the following:

uint64_t *a,*b;
a = new uint64_t[LEN];
b = new uint64_t[LEN];
for( int i=0;i<LEN;i++ ) a[i] = b[i];

With LEN set to 402,653,184 (384 Mi), PCM is reporting 0.72 GB under READ and 6.30 GB under WRITE. Given that each array is 3 GiB, I would expect that both arrays would be read (since processor uses write-allocate), giving a READ of about 6 GiB. I would expect array "a" to be written back, giving a write count of 3 GiB.

GPU monitoring API


I have installed Media SDK and successfully run samples and also FFmpeg with hardware support of Intel Quick Sync technology.

Now I want to estimate the performance of my solution and I need to get load metrics from GPU.

The only tool I've found is /opt/intel/mediasdk/tools/metrics_monitor/_bin/metrics_monitor  but it has strange format and also not perfectly suit my needs.

So I want to know is there any API which I can use in my own program which provide me an interface to GPU metrics?



Intel xeon phi ubuntu

Is there any way to make this card work on some publkick distributions like ubuntu or debian? 

I am a bioinformatic scientist, i dont know that much about programming, and each guides i found on the web failed. 

Is there any (easy) way to make this card work on the latest ubuntu LTS? 

Extracting results based on time ranges

Hello, I am interested in using Vtune to profile a system. I have run a project and gathered the results. I am looking at the hardware event samples for a specific cpu. EG: All hardware events for CPU 0. The problem I am having is that I want to look at the results based on small time intervals. Basically I want to see the results for every 15ms. 

compiler option O0 and O2 generate different results

Hi all,

I am optimizing my code. When I use O2 compiler option, the code runs repeatedly two times, the results are different in each repeat. But when I change to O0 compiler option, the results are the same. What might be the reason?

BTW, I am using CentOS 6.5 and the command line is as follows:

icpc -O2 -DALIGN_OPT=16 -DSSE -ipo main_turbo_decoding_cfunc.cpp turbo_decoding_cfunc.cpp -o turbo_decoding -lrt

Thank you!

Subscribe to Optimization