scheduling

My questions are about warps and scheduling. I'm using NVIDIA Fermi terminology here. My observations are below, are they correct? A. Threads in the same warp execute the same instruction. Each warp includes 32 threads. According to the Fermi Whitepaper: "Fermi’s dual warp scheduler selects two warps, and issues one instruction from each warp to a group of sixteen cores, sixteen load/store units, or four SFUs. " From here, I think a warp(32 threads) is scheduled twice since 16 cores out of 32 are grouped together. Each scheduler issues half of a warp to 16 cores in a cycle, and in all, two

The OS is RHEL 6 (2.6.32). I have isolated a core and am running a compute intensive thread on it. /proc/{thread-id}/status shows one non-voluntary context switch every second. The thread in question is a SCHED_NORMAL thread and I don't want to change this. How can I reduce this number of non-voluntary context switches? Does this depend on any scheduling parameters in /proc/sys/kernel? EDIT : Several responses suggest alternative approaches. Before going that route, I first want to understand why I am getting exactly one non-voluntary context switch per second even over hours of run. For

This is my 1st time trying Spring3's @Scheduled , but found I cannot commit to DB. This is my code : @Service public class ServiceImpl implements Service , Serializable { @Inject private Dao dao; @Override @Scheduled(cron="0 0 * * * ?") @Transactional(rollbackFor=Exception.class) public void hourly() { // get xxx from dao , modify it dao.update(xxx); } } I think it should work , I can see it starts-up hourly and load xxx from DB , but data is not committed to DB. There's been tx:annotation-driven in spring's xml : <bean id="entityManagerFactoryApp" class="org.springframework.orm.jpa

I am looking for a way to modify a process' priority through command line. I found the builtin (bash) nice and the command renice which allow to modify the niceness of the process, but not the actual priority which is calculated by the kernel. Is there a command which allows to set the priority? (Or am I confused between niceness and priority?) Turbo J The priority of a process in linux is dynamic: The longer it runs, the lower its priority will be. A process runs when its actually using the CPU - most processes on a typical Linux box just wait for I/O and thus do not count as running . The

I want to design a lottery scheduler and I need to have a very good (pseudo) random number generator similar to LCG but I was wondering if there are other better choice out there or not? I am specifically looking for random generators written in C. LCG code: unsigned long lcg_rand(unsigned long a) { return (a * 279470273UL) % 4294967291UL; } Also I would like to know if srand() can be used for this purpose or is not highly accurate? If you need simple but decent quality, I would use the upper 32 (or fewer) bits of a 64-bit LCG, possibly with a tempering function applied to the output. When

I have a situation where I need to allocate people to several events. If we just had a price as a factor, it would be fine, but there is a number of factors that come in. First, some background. This is for a non-profit organization that promotes story hours for children that are hospitalized for any reason, so they depend on voluntary work to do so. So, since they rely on people's good will, they give people as much work as people can / want to do, which varies like: Some people can only do mornings, and some other people can only do afternoons; Some people can only do Mondays, and Thursdays,