Re: [Haifux] some additions and eratta to today's lecture

2011-03-21 Thread Nadav Har'El
On Tue, Mar 15, 2011, guy keren wrote about [Haifux] some additions and eratta to today's lecture: 1. etzion asked about controlling the age of dirty pages before pdflush flushes them - the default value is 30 seconds, and can be seen by: cat /proc/sys/vm/dirty_expire_centisecs

Re: [Haifux] some additions and eratta to today's lecture

2011-03-21 Thread guy keren
On Mon, 2011-03-21 at 14:26 +0200, Nadav Har'El wrote: On Tue, Mar 15, 2011, guy keren wrote about [Haifux] some additions and eratta to today's lecture: 1. etzion asked about controlling the age of dirty pages before pdflush flushes them - the default value is 30 seconds, and can

Re: [Haifux] some additions and eratta to today's lecture

2011-03-15 Thread Shachar Raindel
Hijacking the thread to a more general HD discussion. Since there was an interest in SSD (flash) drives, here is a benchmark of normal hard-drives and flash drives: http://techreport.com/articles.x/19330/3 2 points which are easy to see in the graph, and were raised in the discussion yesterday:

Re: [Haifux] some additions and eratta to today's lecture

2011-03-15 Thread Tzafrir Cohen
On Tue, Mar 15, 2011 at 11:00:02AM +0200, Shachar Raindel wrote: Hijacking the thread to a more general HD discussion. And while we're at it, here's the article I mentioned about the funny behaviour of write to SSDs: http://lwn.net/Articles/428584/ Short summary: someone of the Linaro project

[Haifux] some additions and eratta to today's lecture

2011-03-14 Thread guy keren
1. etzion asked about controlling the age of dirty pages before pdflush flushes them - the default value is 30 seconds, and can be seen by: cat /proc/sys/vm/dirty_expire_centisecs (the time there is in milli-seconds). it can be changed by echoing the desired time into that file,

Re: [Haifux] some additions and eratta to today's lecture

2011-03-14 Thread guy keren
someone reminded me about the small trail through the linux kernel link i mentioned. it is: http://www.win.tue.nl/~aeb/linux/vfs/trail.html note that it is from 2001 and relates to kernel 2.4 (or even older) - but the general has not completely changed. you can find a more up-to-date info