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Re: Memory & SWAP [message #9800 is a reply to message #9794]

Tue, 23 January 2007 09:17

xemul
Messages: 248
Registered: November 2005

Senior Member

When you fork your new task inherits all memory from its parent. Thus if your task has allocated 128M of private anonymous mappings and forks new system can potentially eat 256M of memory - if this exceeds privvmpages we don't allow forking.

SWAP isn't limited now - it's just accounted into oomguarpages. When system becomes low of memory it starts to oom kill tasks taking oomguarpages into account.

When VE eats all provvmpages no swapout starts - only when the whole system runs out of mem.

Also note, that freeing memory consists of 3 stages:
1. shrink kernel caches
2. sysncing file caches to disk
3. swapping anonymous pages out

so if kernel caches were shrinked no user pages go away.

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[Message index]

		Memory & SWAP By: devonblzx on Mon, 22 January 2007 21:08
		Re: Memory & SWAP By: rickb on Tue, 23 January 2007 01:15
		Re: Memory & SWAP By: devonblzx on Tue, 23 January 2007 02:15
		Re: Memory & SWAP By: xemul on Tue, 23 January 2007 09:17
		Re: Memory & SWAP By: devonblzx on Wed, 24 January 2007 03:00
		Re: Memory & SWAP By: rickb on Wed, 24 January 2007 04:14
		Re: Memory & SWAP By: devonblzx on Wed, 24 January 2007 05:03
		Re: Memory & SWAP By: rickb on Wed, 24 January 2007 14:27
		Re: Memory & SWAP By: poige on Sun, 18 October 2009 13:10
		Re: Memory & SWAP By: pzYsTorM on Fri, 21 August 2009 09:12

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