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----- Original Message ----- From: "Paul Jakma" <[email protected]> To: "Alexei Roudnev" <[email protected]> Cc: "Michel Py" <[email protected]>; "Nanog" <[email protected]> Sent: Wednesday, August 04, 2004 2:39 AM Subject: Re: Quick question. --- snip --- > Not really.. this is a resource exhaustion problem, and you can not > cure this, given buggy apps, by throwing more CPUs at it. > > Let's say you have some multi-process or multi-threaded application > which regularly spawns/forks new processes/threads, but it is buggy > and prone to having individual processes/threads spin. > > So one spins, but you still have plenty of CPU time left cause you > have two CPUs. Another spins, and the machine starts to crawl. So you > solve this problem by upgrading to a quad-SMP machine. And guess what > happens? :) the second cpu buys you time - it is unlikely you're going to be able to react in time on a busy single cpu box with a runaway process (it launches into a death sprial almost immediately), but you would usually have 10-15 mins on a dual cpu box at a minimum or maybe infinity if you enforce cpu affinity for apps that tend to misbehave. paul
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