Gentoo Archives: gentoo-performance

From: Gyujin Park <gpark@××××××.com>
To: gentoo-performance@l.g.o
Subject: Re: [gentoo-performance] swap?
Date: Sun, 01 Aug 2004 04:58:21
Message-Id: 20040801045817.602E838057@spy23.spymac.net
1 true, this thread was about server not swapping, not a laptop's power consumption
2 during swapping.
3
4 Although, I agree, today laptops are getting faster and software demands are
5 increasing but laptop batteries are always falling behind. PB 17" I have pretty
6 drains quickly.
7
8 I think the best solution for laptop users is to customize their own kernel, and
9 tweak some settings about swap. (which I don't know.. since I am not a guru.)
10
11 I personally never used Linux in a laptop. (I see no reason why, since Mac
12 Panther is Unix Core, BSD... Although I really like Gentoo MAC thing.)
13
14 The server I was dealing with swap is now running alright. It uses swap when it
15 needs to. "swapiness" is there. Kernel 2.6 is loaded. Its running good with other
16 testing servers!!
17
18 I hope Gentoo be the one server OS that people will go with, although this is not
19 entirely up to me. (other people involved with this testing...)
20
21 Tom
22
23 On Sat Jul 31 22:35 , Colin Kingsley <ckingsley@×××××.com> sent:
24
25 >yea, I agree... but thats not what this thread was about.
26 >
27 >not that it should die here, feel free to discuss it. :)
28 >
29 >On Sun, 1 Aug 2004 00:33:15 -0400, Douglas Breault Jr.
30 >genkreton@×××××××.net> wrote:
31 >> Even on laptops swap has a purpose and should be used to increase space but
32 there is a definite lack of control over it beyond the very obscure swapiness
33 variable. It's not horribly bad right now but it seems too many people want to
34 make this worse. The laptop sysctl variable is the closest thing we have
35 unfortunately.
36 >>
37 >> There needs to be a balance between power and performance when necessary. Swap
38 is good stuff sometimes.
39 >>
40 >> On Sun, 1 Aug 2004 00:17:47 -0400
41 >>
42 >>
43 >> Colin Kingsley ckingsley@×××××.com> wrote:
44 >>
45 >> > how is that "disturbing"? you _can_
46 >> > turn off swap for power reasons if you want too.
47 >> >
48 >> > it was a discussion about swap, what were you expecting?
49 >> > by the way, I happen to be on a laptop myself.
50 >> >
51 >> >
52 >> > On Sun, 1 Aug 2004 00:06:12 -0400, Douglas Breault Jr.
53 >> > genkreton@×××××××.net> wrote:
54 >> > > The dsturbing thing about those threads you posted up is that they
55 completely ignore those people running laptops who may also want to not swap
56 often because it spins up the harddrive and causes a spike in power consumption
57 everytime this happens.
58 >> > > This is a problem I've experience with the CK patch set.
59 >> > >
60 >> > > On Fri, 30 Jul 2004 21:22:17 +0200
61 >> > >
62 >> > >
63 >> > > "Florian Koenig" k0255220@××××××××××××××××××××.at> wrote:
64 >> > >
65 >> > > > > > Also, when I do
66 >> > > > > >
67 >> > > > > > free
68 >> > > > > >
69 >> > > > > > it shows no swap is used even though physical memory level is 98%.
70 >> > > > >
71 >> > > > > free shows no swap used on my system either. and 90% or more physical
72 >> > > > > memory use is standard for the linux kernel.
73 >> > > >
74 >> > > > Exactly. In contrast to Windows NT/2000/XP, which tries to swap out as
75 much pages as possible, Linux tries to keep the memory mostly filled. Lots of the
76 memory gets used as cache and buffer so you might actually gain some performance.
77 >> > > >
78 >> > > > The difference between Windows and Linux stems from their different
79 origins. Linux/Unix was always meant to be a server system where the set of
80 running processes doesn't change that often. Therefore it tries to keep pages in
81 memory for as long as possible.
82 >> > > >
83 >> > > > Windows' approach to the problem is geared to desktop performance and so
84 it swaps out 'unused' pages as soon as possible to free memory and keep startup
85 time short for programs being loaded.
86 >> > > >
87 >> > > > The behaviour of Linux is actually hotly debated by the developers as
88 you can see on these two pages, which btw also include some hints on how to tune
89 swapping:
90 >> > > >
91 >> > > > http://kerneltrap.org/node/view/3000
92 >> > > > http://kerneltrap.org/node/view/3202
93 >> > > >
94 >> > > > Have a nice weekend and kind regards
95 >> > > > floki
96 >> > > >
97 >> > > >
98 >> > > > --
99 >> > > > gentoo-performance@g.o mailing list
100 >> > > >
101 >> > >
102 >> > >
103 >> > >
104 >> >
105 >> > --
106 >> > gentoo-performance@g.o mailing list
107 >> >
108 >>
109 >>
110 >>
111 >
112 >--
113 >gentoo-performance@g.o mailing list
114 >
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Replies

Subject Author
Re: [gentoo-performance] swap? Colin Kingsley <ckingsley@×××××.com>