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Comment Re:Question: (Score 4, Interesting) 101

by PoochieReds (#36051836) Attached to: Writing Linux Kernel Functions In CUDA With KGPU

There are also other concerns than the context switch overhead...particularly when dealing with filesystems or data storage devices.

For instance, suppose part of your userspace daemon gets swapped out, and you now need to upcall to userspace. That part that got paged out then has to be paged back in. If memory is tight, then the kernel may have to free some memory, and it may decide to flush out dirty data to the filesystem or device that is dependent on the userspace daemon. At that point, you're effectively deadlocked.

Most of those sorts of problems can be overcome with careful coding and making sure the important parts of the daemon are mlocked, but you do have to be careful and it's not always straightforward to do that.

Comment Re:Fixes? (Score 1) 228

by PoochieReds (#34209362) Attached to: Red Hat Releases RHEL 6

I assume you're talking about client-side performance? If so, then yes it should be much better in RHEL6.

FWIW, The NFS tools don't really do much once you've got the filesystem mounted. (Ok, that's not 100% true with NFSv4 or Kerberized NFS but it is for the most part). Performance problems like this are generally in the kernel. I've got a patchset queued up to try and improve NFS write performance in RHEL5, but it probably won't go in until 5.7.

See this page if you want to test out what I have queued up so far. It's still pretty rough, but the results so far are quite promising:

        http://people.redhat.com/jlayton/

If you have a support contract, you should open a support case on this. Typically, performance problems are all about numbers so if you can quantify the problems you're seeing then we should be able to help.
Security

Ants Vs. Worms — Computer Security Mimics Nature 104

Posted by Soulskill from the incompatible-with-raid dept.
An anonymous reader writes with this excerpt from Help Net Security: "In the never-ending battle to protect computer networks from intruders, security experts are deploying a new defense modeled after one of nature's hardiest creatures — the ant. Unlike traditional security devices, which are static, these 'digital ants' wander through computer networks looking for threats ... When a digital ant detects a threat, it doesn't take long for an army of ants to converge at that location, drawing the attention of human operators who step in to investigate. 'Our idea is to deploy 3,000 different types of digital ants, each looking for evidence of a threat,' [says Wake Forest Professor of Computer Science Errin Fulp.] 'As they move about the network, they leave digital trails modeled after the scent trails ants in nature use to guide other ants. Each time a digital ant identifies some evidence, it is programmed to leave behind a stronger scent. Stronger scent trails attract more ants, producing the swarm that marks a potential computer infection.'"
Government

Obama Wants Broadband, Computers Part of Stimulus 901

Posted by CmdrTaco from the that-would-stimulate-me dept.
damn_registrars writes "President-elect Barack Obama announced in his radio address that his administration's economic stimulus package will include investing in computers and broadband for education. 'To help our children compete in a 21st century economy, we need to send them to 21st century schools.' He also said it is 'unacceptable' that the US ranks 15th in broadband adoption." No doubt with free spyware and internet filtering. You know... for the kids.
Privacy

ACLU Creates Map of US "Constitution-Free Zone" 979

Posted by kdawson from the stay-well-inland dept.
trackpick points out a recent ACLU initiative to publicize a recent expansion of authority claimed by the Border Patrol to stop and search individuals up to 100 miles from any US border. They have created a map of what they call the US Constitution-Free Zone. "Using data provided by the US Census Bureau, the ACLU has determined that nearly 2/3 of the entire US population (197.4 million people) live within 100 miles of the US land and coastal borders. The government is assuming extraordinary powers to stop and search individuals within this zone. This is not just about the border: This 'Constitution-Free Zone' includes most of the nation's largest metropolitan areas.'"

Comment HD channels w/ no HD programming (Score 4, Interesting) 292

by PoochieReds (#24344749) Attached to: Lack of Bandwidth Oversight Damages HDTV Quality

Not exactly the same but my current gripe with my satellite provider (DirecTV) is that I bought one of their HD channel packages, and a number of the channels that are listed as HD channels never actually have any HD programs on them. They're all standard def. The Disney channel, for instance is listed as a high def channel, but I've never seen a single high-def program on it (I even surfed the channel guide through several days to see if anything ever did).

Total fraudulent BS...

I'd drop 'em like a hot potato tomorrow but the wife is addicted to the crap that comes on there...

*sigh*
Censorship

Sen. Ted Stevens Introduces "Son of DOPA" 221

Posted by kdawson from the tubes-tied dept.
DJCacophony writes "Ted 'series of tubes' Stevens has introduced a bill, going by the interim name S.49, that aims to block access to interactive websites from schools and libraries. The wording of the bill is vague enough to apply to Wikipedia, MySpace (and other social networking sites), and potentially even to blogs. The bill is apparently so similar to the failed Deleting Online Predators Act of last year that it has been termed 'Son of DOPA' by some." Stevens introduced S.49, the text of which is not yet available, on the opening day of the legislative session.

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