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Date: Sat, 10 Oct 2015 23:51:48 -0400 From: Dave Goel <deego3@...il.com> To: "Theodore Ts'o" <tytso@....edu>, Dave Goel <deego3@...il.com>, linux-kernel@...r.kernel.org Subject: Re: [Linux] Linux PID algorithm is BRAINDEAD! Hi Ted, Thanks for responding. Fair points all of them. I would like to take exception to one of them, the bottleneck part: > The biggest problem is that accessing this free pid queue is now > a locking bottleneck --- especially on a very large NUMA system That was exactly what I was trying to say towards the end: the the queue idea or implementation need not be strict. No one cares if instead of grabbing the very firts aof the queue, you grab, say, the third element. The /only/ real requirement is that newly entered elements not go near the head of the queue. I would argue that bottleneck or resource locking doesn't exist at all: If you have n cpu's, you can have n queues, albeit each now smaller. (Or, equivalently, the cpu's deciding to divvy up the queue into a mod n space.). And, the populator pushing into them in a round-robin fashion. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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