When I boot up I have about 500 meg free memory. After some browsing and
mail/news reading openening and closing browsers I end up with about 47k
free after closing everything. Is there a way to flush out the memory
without rebooting? Something about Firefox and Thunderbird don't clean
up after they shutdown.


--
Blattus Slafaly ? 3 :) 7/8

Blattus Slafaly 0/00 ? ? ? wrote:
> When I boot up I have about 500 meg free memory. After some browsing and
> mail/news reading openening and closing browsers I end up with about 47k
> free after closing everything. Is there a way to flush out the memory
> without rebooting? Something about Firefox and Thunderbird don't clean
> up after they shutdown.
>
>
Wait, I found it. # echo 1 > /proc/sys/vm/drop_caches

Wow, I had 701 meg free after that.

--
Blattus Slafaly ? 3 :) 7/8

Blattus Slafaly 0/00 ? ? ? wrote:
> When I boot up I have about 500 meg free memory. After some browsing and
> mail/news reading openening and closing browsers I end up with about 47k
> free after closing everything. Is there a way to flush out the memory
> without rebooting? Something about Firefox and Thunderbird don't clean
> up after they shutdown.

And what is the problem with that? The fact that there is something in
memory doesn't mean anything. You bought and payed for the memory, so
use it. The fact that things are still there afterwards is a good
thing.

If the memory is nedded for something else, it will clean it. If not
then not.

houghi
--
I do not want life insurance.
I want all people to be genuinely grieving when I die.

houghi

houghi wrote:
> Blattus Slafaly 0/00 ? ? ? wrote:
>> When I boot up I have about 500 meg free memory. After some browsing and
>> mail/news reading openening and closing browsers I end up with about 47k
>> free after closing everything. Is there a way to flush out the memory
>> without rebooting? Something about Firefox and Thunderbird don't clean
>> up after they shutdown.
>
> And what is the problem with that? The fact that there is something in
> memory doesn't mean anything. You bought and payed for the memory, so
> use it. The fact that things are still there afterwards is a good
> thing.
>
> If the memory is nedded for something else, it will clean it. If not
> then not.
>
> houghi

Well that's not entirely true. As I ran more and more things I noticed
that the free memory stayed low and the system began using swap memory
instead of cleaning out the ram. That can slow things down. I suppose it
depends on how smart the program is as to what memory cleaning it will do.

--
Blattus Slafaly ? 3 :) 7/8

Blattus Slafaly 0/00 ? ? ? wrote:
>> If the memory is nedded for something else, it will clean it. If not
>> then not.
>>
>> houghi
>
> Well that's not entirely true. As I ran more and more things I noticed
> that the free memory stayed low and the system began using swap memory
> instead of cleaning out the ram. That can slow things down. I suppose it
> depends on how smart the program is as to what memory cleaning it will do.

Using what program? Also is this something that happens all the time, or
more an academic discusion of something that might sometimes happen, but
does not affect the standard normal everyday user.

If memory is not used, then flushing the momory should not matter,
because it is not used. If you flush memory all the time, then you do
not have enough memory. Flushing does not help it. It will just slow
down the program you flush the memory from.

And yes, some swap might be used as well for each program.

In general the system will select the best method in real world
situations (the extremely odd situation as an obvious exception)

Seriously, it is not worth the time to look into it. Linux knows better
what to do.

houghi
--
I do not want life insurance.
I want all people to be genuinely grieving when I die.

houghi

Blattus Slafaly 0/00 ? ? ? <boobooililililil@roadrunner.com> wrote:
>Blattus Slafaly 0/00 ? ? ? wrote:
>> When I boot up I have about 500 meg free memory. After some browsing and
>> mail/news reading openening and closing browsers I end up with about 47k
>> free after closing everything. Is there a way to flush out the memory
>> without rebooting? Something about Firefox and Thunderbird don't clean
>> up after they shutdown.
>>
>>
>Wait, I found it. # echo 1 > /proc/sys/vm/drop_caches

>Wow, I had 701 meg free after that.

Yes, but your machine will run more slowly.

You have made a mistake. As your system runs, memory is used as
a cache for programs, files, etc. Try, for example, to load
Firefox the first time since rebooting. Use it a bit and then
close it. Now reopen it. See how much faster it is the second
time?

If a program you run needs more memory, the operating system will
flush memory as needed. It will either dump what already exists
on disk or, if need be, swap memory out, though this should almost
never happen if you have a reasonable amount of memory installed.

Look at it this way: why should all that beautiful memory go to
waste. Consider how much faster memory access is than disk access.
ALL modern operating systems use memory as a cache for the same
reason.

--
--- Paul J. Gans

On Wed, 19 Mar 2008, Blattus Slafaly 0/00 ? ? ? wrote:-

>Well that's not entirely true. As I ran more and more things I noticed
>that the free memory stayed low and the system began using swap memory
>instead of cleaning out the ram.

In that case, the programs that were using the memory were still open
and hadn't released memory after they'd finished with it.

>That can slow things down.

You're telling me. I have one system that has 1GB of memory. Due to the
applications it's running normally (bind, mysql, etc.), and the fact
it's busy rescaling[0] virtually all the wallpapers houghi included in
his 10GB wallpaper pack, it's presently using 1.5GiB of swap. To make
matters worse I'm also using KDE (which in houghi sees as evil :) ) and
konqueror is quite sluggish at refreshing the directories, and KDE
itself is also sluggish at changing from one desktop to another.

>I suppose it depends on how smart the program is as to what memory
>cleaning it will do.

Some programs aren't very nice. They will often retain memory they've
used just in case they want to reuse it again in the future. Others
release the memory as soon as they are done with it. Still others are
mixed. And then there are the rare ones that forget they have allocated
memory and keep requesting more. These ones are the really nasty ones
because, until their memory leaks are fixed, their memory usage tends to
grow until either the user terminates the program, or they fall over
because the kernel denies a request for more memory.


[0] And splitting them up into directories using the names of the
persons.

Regards,
David Bolt

--
www.davjam.org/lifetype/ www.distributed.net: OGR@100Mnodes, RC5-72@15Mkeys
SUSE 10.1 32bit | openSUSE 10.2 32bit | openSUSE 10.3 32bit | openSUSE 11.0a1
SUSE 10.1 64bit | openSUSE 10.2 64bit | openSUSE 10.3 64bit
RISC OS 3.6 | TOS 4.02 | openSUSE 10.3 PPC |RISC OS 3.11

Blattus Slafaly 0/00 ? ? ? wrote:
> When I boot up I have about 500 meg free memory. After some browsing and
> mail/news reading openening and closing browsers I end up with about 47k
> free after closing everything. Is there a way to flush out the memory
> without rebooting? Something about Firefox and Thunderbird don't clean
> up after they shutdown.

If you do "free -m" in a console, you'll get something like this:

total used free shared buffers cached
Mem: 749 741 7 0 6 651
-/+ buffers/cache: 83 665
Swap: 2000 2 1997

It says "used 741" (MB). However, what you really have is in the next
line that says "-/+ buffers/cache". As you can see, in reality I have
only 83MB used with 665MB free.

You don't need to "flush the memory" or anything like that. In fact, if
you do, this will delete the buffers/cache and make your system slower.
Memory management is different from what MS Windows does, so the
notion of "free memory" is different too; there is "needed" memory,
"used" memory and "free" memory, not just "used" and "feee".

Btw, the above machine is a 100 users server that has been running for
20 days without reboot now ;)

David Bolt wrote:
> You're telling me. I have one system that has 1GB of memory. Due to the
> applications it's running normally (bind, mysql, etc.), and the fact
> it's busy rescaling[0] virtually all the wallpapers houghi included in
> his 10GB wallpaper pack, it's presently using 1.5GiB of swap. To make
> matters worse I'm also using KDE (which in houghi sees as evil :) ) and
> konqueror is quite sluggish at refreshing the directories, and KDE
> itself is also sluggish at changing from one desktop to another.

Don't use KDE and your 10GB would fly. :-D

In all seriousness, I have 1GB as well and have no issues going from one
desktop to another. Never in any of the years I do have my system. Not
on Linux anyway. On Windows I have something that simulates multiple
desktops and it is unusable.

Oh and with Linux, I mean also mean KDE, evil GNOMEa and delightfull
Windowmaker.

houghi
--
I do not want life insurance.
I want all people to be genuinely grieving when I die.

houghi

houghi wrote:
> David Bolt wrote:
>> You're telling me. I have one system that has 1GB of memory. Due to the
>> applications it's running normally (bind, mysql, etc.), and the fact
>> it's busy rescaling[0] virtually all the wallpapers houghi included in
>> his 10GB wallpaper pack, it's presently using 1.5GiB of swap. To make
>> matters worse I'm also using KDE (which in houghi sees as evil :) ) and
>> konqueror is quite sluggish at refreshing the directories, and KDE
>> itself is also sluggish at changing from one desktop to another.
>
> Don't use KDE and your 10GB would fly. :-D
>
> In all seriousness, I have 1GB as well and have no issues going from one
> desktop to another. Never in any of the years I do have my system. Not
> on Linux anyway. On Windows I have something that simulates multiple
> desktops and it is unusable.
>
> Oh and with Linux, I mean also mean KDE, evil GNOMEa and delightfull
> Windowmaker.

KDE doesn't really seem that memory hungry to me. CPU hungry maybe, but
with a Core 2 Duo E6600 I can't really tell :P After booting to
runlevel 5 into KDE, memory usage is 106MB. Runlevel 3's initial usage
is 74MB.

With KDevelop, Amarok, Opera (does that count?) loaded, and using the
Crystal decorations Curve style with all eye candy enabled, RAM usage is
about 350MB. I think that's very good, and this is an x86-64 system
(uses a bit more RAM than the 32-bit version). :P

PS:
Kerry Beagle is disabled (uninstalled). I think RAM usage would be
about 400MB with that ;P