[gentoo-user] Optimizations for SSD netbook

[gentoo-user] Optimizations for SSD netbook

[Grant]

My girlfriend is at her wit's end with her SSD netbook and is now
hogging my laptop.  Her netbook has 1GB RAM that could be upgraded to
1.5GB, but I've read that it's a pain.  It already runs xfce4, and
I've just made these optimizations based on past discussions:

1. CFLAGS="-march=prescott -0s -pipe -fomit-frame-pointer -ssse3"
2. added elevator=noop as a boot parameter
3. disabled DRI to save 32MB RAM
4. removed the swap partition from /etc/fstab

Am I missing anything significant?  I've read that it's good to set up
/tmp in RAM.  How can I do that?  In /etc/fstab I have:

shm /dev/shm tmpfs nodev,nosuid,noexec

Is that related?

- Grant

Re: [gentoo-user] Optimizations for SSD netbook

[Mike Kazantsev]

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On Fri, 29 May 2009 17:24:06 -0700
Grant <emailgrant@gmail.com> wrote:

> Am I missing anything significant?  I've read that it's good to set up
> /tmp in RAM.  How can I do that?  In /etc/fstab I have:
> 
> shm /dev/shm tmpfs nodev,nosuid,noexec
> 
> Is that related?

Only in a way that it is tmpfs as well.

/tmp is rarely used and then mostly for stuff like different IPC
pointers like unix sockets, which lay no burden on any disk.

I've seen some suggestions of mounting /var/tmp/portage as tmpfs
hovewer, but the logic of it escapes me: you loose persistency for
nothing - any free memory will be used for FS cache anyway, so if
emerge is working on these files they'll be 99.9% in-memory anyway.

I only found it useful for RAM-challenged machines which can't spare
any megabytes for FS cache so I'm mostly curious about it's application
in home-like environment, as well.

-- 
Mike Kazantsev // fraggod.net

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Re: [gentoo-user] Optimizations for SSD netbook

[Florian Philipp]

Grant schrieb:
> My girlfriend is at her wit's end with her SSD netbook and is now
> hogging my laptop.  Her netbook has 1GB RAM that could be upgraded to
> 1.5GB, but I've read that it's a pain.  It already runs xfce4, and
> I've just made these optimizations based on past discussions:
> 
> 1. CFLAGS="-march=prescott -0s -pipe -fomit-frame-pointer -ssse3"
> 2. added elevator=noop as a boot parameter

I remember that I've given this second advice. Since then I've read in
the German computer journal c't [1] that CFQ has a detection for SSDs
since 2.6.28 and now is the best choice for these devices.

> 3. disabled DRI to save 32MB RAM
> 4. removed the swap partition from /etc/fstab
> 
> Am I missing anything significant?  I've read that it's good to set up
> /tmp in RAM.  How can I do that? In /etc/fstab I have:
> 
> shm /dev/shm tmpfs nodev,nosuid,noexec
> 
> Is that related?
> 

Yup, the entry should read:
tmp /tmp tmpfs default 0 0

The first entry is just a name. You can name it in every way you want it.

For further tweaks: Do you use Firefox? I've read that it uses fsync()
when writing to its sqlite backend. This is a really good thing because
it reduces the risk of loosing data but you might (and can) disable this
to increase performance and reduce wear. I don't have a link at hand but
it shouldn't be to hard to find.

[1]c't 11/2009 page 101

Re: [gentoo-user] Optimizations for SSD netbook

[Grant]

>> My girlfriend is at her wit's end with her SSD netbook and is now
>> hogging my laptop.  Her netbook has 1GB RAM that could be upgraded to
>> 1.5GB, but I've read that it's a pain.  It already runs xfce4, and
>> I've just made these optimizations based on past discussions:
>>
>> 1. CFLAGS="-march=prescott -0s -pipe -fomit-frame-pointer -ssse3"
>> 2. added elevator=noop as a boot parameter
>
> I remember that I've given this second advice. Since then I've read in
> the German computer journal c't [1] that CFQ has a detection for SSDs
> since 2.6.28 and now is the best choice for these devices.

OK, do I need a boot parameter if I've set CFQ as the default IO
scheduler in the kernel config?

>> 3. disabled DRI to save 32MB RAM
>> 4. removed the swap partition from /etc/fstab
>>
>> Am I missing anything significant?  I've read that it's good to set up
>> /tmp in RAM.  How can I do that? In /etc/fstab I have:
>>
>> shm /dev/shm tmpfs nodev,nosuid,noexec
>>
>> Is that related?
>>
>
> Yup, the entry should read:
> tmp /tmp tmpfs default 0 0

Do you think mounting /tmp in RAM is worthwhile?  Mike doesn't seem to
think too highly of it.

> The first entry is just a name. You can name it in every way you want it.
>
> For further tweaks: Do you use Firefox? I've read that it uses fsync()
> when writing to its sqlite backend. This is a really good thing because
> it reduces the risk of loosing data but you might (and can) disable this
> to increase performance and reduce wear. I don't have a link at hand but
> it shouldn't be to hard to find.

There is some interesting info on disabling fsync here:

http://www.flamingspork.com/projects/libeatmydata/

Sounds kinda dangerous. :)

- Grant

Re: [gentoo-user] Optimizations for SSD netbook

[Mike Kazantsev]

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On Sat, 30 May 2009 07:08:55 -0700
Grant <emailgrant@gmail.com> wrote:

> >> 2. added elevator=noop as a boot parameter
> >
> > I remember that I've given this second advice. Since then I've read in
> > the German computer journal c't [1] that CFQ has a detection for SSDs
> > since 2.6.28 and now is the best choice for these devices.
> 
> OK, do I need a boot parameter if I've set CFQ as the default IO
> scheduler in the kernel config?

No, that's what default switch is there for.


> > Yup, the entry should read:
> > tmp /tmp tmpfs default 0 0

I'd also suggest to explicitly specify max size of tmpfs mount, since
system locking because of wrong cp command is probably the last thing
you want. Argument is "size=" (see man 8 mount).


> Do you think mounting /tmp in RAM is worthwhile?  Mike doesn't seem to
> think too highly of it.

I guess accelerated fsync and reduced disk wear should be a nice plus
for SSD device, provided the path in question is constanly used for
writing which really might be the case with files, created in /tmp by
various mktemp implementations (like python's) which I haven't really
thought about, so I think I might be wrong about the issue here, sorry.


-- 
Mike Kazantsev // fraggod.net

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Re: [gentoo-user] Optimizations for SSD netbook

[Grant]

>> >> 2. added elevator=noop as a boot parameter
>> >
>> > I remember that I've given this second advice. Since then I've read in
>> > the German computer journal c't [1] that CFQ has a detection for SSDs
>> > since 2.6.28 and now is the best choice for these devices.
>>
>> OK, do I need a boot parameter if I've set CFQ as the default IO
>> scheduler in the kernel config?
>
> No, that's what default switch is there for.
>
>
>> > Yup, the entry should read:
>> > tmp /tmp tmpfs default 0 0
>
> I'd also suggest to explicitly specify max size of tmpfs mount, since
> system locking because of wrong cp command is probably the last thing
> you want. Argument is "size=" (see man 8 mount).
>
>
>> Do you think mounting /tmp in RAM is worthwhile?  Mike doesn't seem to
>> think too highly of it.
>
> I guess accelerated fsync and reduced disk wear should be a nice plus
> for SSD device, provided the path in question is constanly used for
> writing which really might be the case with files, created in /tmp by
> various mktemp implementations (like python's) which I haven't really
> thought about, so I think I might be wrong about the issue here, sorry.

Thanks guys.  I think the /tmp trick made a good difference.  The last
thing I can think of is pruning the kernel way down.  I think it's
mostly default.

- Grant

Re: [gentoo-user] Optimizations for SSD netbook

[Neil Bothwick]

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On Sat, 30 May 2009 07:08:55 -0700, Grant wrote:

> Do you think mounting /tmp in RAM is worthwhile?  Mike doesn't seem to
> think too highly of it.

I do, especially on an SSD, but with any device it reduces disk access,
which is a good thing.


-- 
Neil Bothwick

April Fools! You're really in a holodeck simulation!

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