Comments on: Swap vs. no swap

By: Alexander Sandler

Alexander Sandler — Sun, 05 Feb 2012 20:52:51 +0000

@Dima Simple. Because kernel had a reason to swap these 5G out of memory and didn't have a reason the return them back to memory again. The sheer fact that you have free memory, doesn't mean kernel can bring all swap contents back to RAM. It will do so on demand.

Reply - @Dima<\/a>\r\nSimple. Because kernel had a reason to swap these 5G out of memory and didn\'t have a reason the return them back to memory again. The sheer fact that you have free memory, doesn\'t mean kernel can bring all swap contents back to RAM. It will do so on demand.'); return false;">Quote

By: Dima

Dima — Tue, 25 Oct 2011 15:36:11 +0000

Can somebody please explain this: [553]=> free -m total used free shared buffers cached Mem: 20116 2845 17271 0 12 333 -/+ buffers/cache: 2499 17617 Swap: 30485 5374 25111 I got 17G of free memory, yet over 5G is swapped out, making my UI literally freeze for seconds. Why is it using swap at all with all the free memory bleeding out of its ears?

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By: Alexander Sandler

Alexander Sandler — Wed, 21 Sep 2011 09:21:39 +0000

@user There's one case where swap is very useful and actually this is where it used most of the time. This is during RAM usage spikes.

Reply - @user<\/a>\r\nThere\'s one case where swap is very useful and actually this is where it used most of the time. This is during RAM usage spikes.'); return false;">Quote

By: user

user — Wed, 21 Sep 2011 01:28:40 +0000

Swap is not panacea. When swap is off and system runs out of memory - it HSLTS IIMEDIATELY after all RAM is full. When swap is on and system runs out of memory - it became almost hooked up and unresponsive with permanent swapping process which ends up with same result HALT but LATER. In any case swaping did not save system from run out of memory. It just make system death more prolonged and more painful (at least for HDD). I believe on average desktop usage there is no reason to use swap when RAM is 4Gb or more. Suspend-to-disk is another story. I have 1Gb on my PC and feels comfortable without swap but ususally I mount 1Gb swap partition which is untouched by system most of the time... BTW, I use KDE and it perfectly fits in 1Gb RAM even with running FF with dozens tabs.

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By: Alexander Sandler

Alexander Sandler — Thu, 15 Sep 2011 09:07:30 +0000

@Cormac No. I can't. Sorry.

Reply - @Cormac<\/a>\r\nNo. I can\'t. Sorry.'); return false;">Quote

By: Cormac

Cormac — Mon, 22 Aug 2011 20:17:57 +0000

@Alexander Sandler - Could you point out the leak in the following Java code? Thanks. public class MemLeak { public static void main(String [] args){ while(true){ System.out.println("I'm a memory leak...am I?"); Thread.sleep(5000); } } }

Reply - @Alexander Sandler<\/a> - Could you point out the leak in the following Java code? Thanks.\r\n\r\npublic class MemLeak {\r\n\r\n public static void main(String [] args){\r\n while(true){\r\n System.out.println(\"I\'m a memory leak...am I?\");\r\n Thread.sleep(5000);\r\n }\r\n }\r\n}'); return false;">Quote

By: Alexander Sandler

Alexander Sandler — Mon, 22 Aug 2011 19:53:40 +0000

@Cormac Yes.

Reply - @Cormac<\/a>\r\nYes.'); return false;">Quote

By: Cormac

Cormac — Mon, 08 Aug 2011 14:00:44 +0000

All programs have memory leaks -- are you for real?

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By: Why Linux Consumes Available Memory? | LinuxReaders

Why Linux Consumes Available Memory? | LinuxReaders — Wed, 15 Dec 2010 13:42:51 +0000

[...] Article 2 Linux uses all available memory to do I/O cache – that is to save portions of the hard disk space and to serve it straight from the memory avoiding relatively long disk access. This is why for instance when you copy several large files from one place to another several times in a row, second copy takes significantly fewer time then the first. This is also the reason why, in Linux, it takes a second to write a megabyte to a floppy disk, a device known for its slowliness – the data being written to the memory and not to an actual disk. [...]

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By: Alexander Sandler

Alexander Sandler — Fri, 18 Dec 2009 20:45:48 +0000

@Computer Support Thanks. I'll check this out. (What's K-Meleon for heaven's sake?)

Reply - @Computer Support<\/a>\r\nThanks. I\'ll check this out.\r\n(What\'s K-Meleon for heaven\'s sake?)'); return false;">Quote