Viraj's Weblog

Interesting view on improving application performance:

Application slimming: There seems to be a common fallacy among programmers that using memory is good: on current hardware it is often much faster to recompute values than to have to reference memory to get a precomputed value. A full cache miss can be hundreds of cycles, and hundreds of times the power consumption of an instruction that hits in the first level cache. Making things smaller almost always makes them faster (and lower power). Similarly, it can be much faster to redraw an area of the screen than to copy a saved image from RAM to a screen buffer. Many programmer's presumptions are now completely incorrect and we need to reeducate ourselves.

From Steven Miles' Oath Betrayed:

Dilawar was a twenty-two-year-old farmer and taxi driver, whom American soldiers tortured to death over five days at Bagram Collection Point in Afghanistan in December 2002. When the soldiers pulled a sandbag over his head, Dilawar complained that he could not breathe. He was then shackled and suspended from his arms for hours, denied water, and beaten so severely that his legs would have been amputated had he survived. When he was beaten with a baton, he would cry "Allah, Allah!," which guards found so amusing that they beat him some more just to hear him cry. During his final interrogation, soldiers told the delirious, injured prisoner that he would get medical attention after the session. Instead, he was returned to a cell and chained to the ceiling. Several hours later, a physician found him dead. By then, the interrogators had concluded that Dilawar was innocent and had simply been picked up after driving his new taxi by the wrong place at the wrong time.
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An autopsy on December 13 found that Dilawar's death was a homicide, caused by extensive and severe "blunt force injuries to lower extremities complicating coronary artery disease" (inexplicably, "coronary artery disease" is typed on the death certificate in a different font). The Pentagon reported that the prisoner died of natural causes. Later, a coroner testified that Dilawar's legs were "pulpified" and that the body looked as if it had been "run over by a truck." Soldiers delivered the body and an English-language death certificate to his wife and two daughters in January 2003. The family could not read English.
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Army criminal investigators waited sixteen months to begin investigating Dilawar's death. They found probable cause to charge twenty-seven soldiers with various roles in causing and concealing the death, including a charge of withholding medical care. No one was charged with murder. Five of the fifteen who were prosecuted have pleaded guilty to assault and other crimes. The harshest punishment received was five months in a military prison. One soldier was convicted of maiming, assault, maltreatment, and making a false statement; he was demoted and honorably discharged... One of his brothers, Shahpoor, reacted to the sentences this way: "I am angry with them, but this was the will of God. God is great, and God will punish them." Vice Admiral Church identified Dilawar's death as one in which medical personnel might have tried to conceal the abuse of a prisoner.