Swap (and low memory) performance

[vinnywright]

my swap partition gets used quite often ,,,, just watching a vid or DVD will use a little and when recoding audio/video .
my system has 4Gig of RAM
see just got done watching a 3+ Hr DVD

vinny@Vinnys-HP-G62:~$ free
total used free shared buffers cached
Mem: 3844396 3619436 224960 0 2020184 495592
-/+ buffers/cache: 1103660 2740736
Swap: 4096536 2384 4094152

VINNY

[SteveRiley]

The only reason I keep a swap partition is for hibernation.

[luckyone]

As noted an SSD gives great bang for the buck. However some dx'ing is needed per the swap usage. I regularly run three different Browsers with 4 to 8 tabs open, a VM, at least one instance of Dolphin. And probably a partridge in a pear tree if I bothered to look closely. I have never seen more than 3.4 GB of my 4 GB of RAM used. I have yet to see swap (a partition) used at all. Zero. Zilch. Nada. I run KDE all the time. I have an old PC. I'm very happy with the responsiveness of my system except for the amount of time that it takes to give me a logon after a lock either a manual one or a screensaver one. It takes a couple of seconds.
I am still running HDDs, both 7200 rpm. Both SATA II.

Of course I'm getting slower also, but that's for another thread.

[SecretCode]

This problem seems to have stopped for me. For a while at least!

... I find that it's when paging out/in is taking place that the system grinds to a halt. ...

Keen to hear from others as well, if anyone finds that performance is bearable when the system starts swapping.

It occurred to me that I hadn't experienced such an usable slowdown for a while - but nevertheless I was using some swap - and of course there was some performance impact, but no more than regular IO. Presumably some kernel update has fixed some specific issue. I certainly haven't done anything concrete to address it.

[GreyGeek]

Another possibility is IRQ problems. Powertop should help determine how your interrupts are working.
Here's mine:

226 wakeups/second
      0.8 ms/s      61.2        Timer          tick_sched_timer
             15.8 ms/s      24.8        Process        /usr/bin/ksysguard
            128.4 µs/s      19.3        kWork          ieee80211_iface_work
              3.6 ms/s      10.3        Process        /usr/bin/X :0 vt7 -br -nolisten tcp -aut
              1.4 ms/s       9.8        Process        dbus-daemon --system --fork --activation
            278.7 µs/s      10.0        Process        /usr/sbin/bumblebeed --use-syslog
             95.2 µs/s       8.3        Process        [rtsx-polling]
            197.8 µs/s       7.7        Timer          hrtimer_wakeup
              1.1 ms/s       7.1        Process        kwin -session 101b7188189177000134408930
              2.3 ms/s       6.2        Process        /usr/bin/python -O /usr/share/wicd/daemo
              6.3 ms/s       4.1        Process        ksysguardd
              0.9 ms/s       5.9        Interrupt      [6] tasklet(softirq)
            144.6 µs/s       4.8        Process        [ksoftirqd/4]
              0.9 ms/s       4.3        Process        /usr/bin/python -O /usr/share/wicd/daemo
              1.7 ms/s       2.7        Process        /usr/bin/plasma-desktop
            378.4 µs/s       2.4        Process        /usr/bin/konsole
            186.9 µs/s       2.2        Process        /usr/sbin/mysqld --defaults-file=/home/j
             84.4 µs/s       2.0        Process        /usr/lib/chromium-browser/chromium-brows
              1.9 ms/s       1.2        Process        wicd

[claydoh]

Ok the dell is up and running

seems my drive is slow and pokey







Its a 4400 rpm drive, lol! but my old ATA drive is about as fast

New drive , replacing a second dead drive

sudo hdparm -t /dev/sda

/dev/sda:
 Timing buffered disk reads: 570 MB in  3.01 seconds = 189.66 M

/dev/sda:


ATA device, with non-removable media
        Model Number:       KINGSTON SV200S364G                     
        Serial Number:      Z19A30MEKATK        
        Firmware Revision:  E120506a
        Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
Standards:
        Supported: 9 8 7 6 5 
        Likely used: 9
Configuration:
        Logical         max     current
        cylinders       16383   16383
        heads           16      16
        sectors/track   63      63
        --
        CHS current addressable sectors:   16514064
        LBA    user addressable sectors:  125045424
        LBA48  user addressable sectors:  125045424
        Logical  Sector size:                   512 bytes
        Physical Sector size:                   512 bytes
        Logical Sector-0 offset:                  0 bytes
        device size with M = 1024*1024:       61057 MBytes
        device size with M = 1000*1000:       64023 MBytes (64 GB)
        cache/buffer size  = unknown
        Form Factor: 2.5 inch
        Nominal Media Rotation Rate: Solid State Device

Not bad for 50 bucks at Staples

[claydoh]

Ok the dell is up and running

seems my drive is slow and pokey

ATA device, with non-removable media
Model Number: TOSHIBA MK2035GSS
Serial Number: 97BVFDRTS
Firmware Revision: DK020M
Standards:
Supported: 7 6 5 4
Likely used: 8
Configuration:
Logical max current
cylinders 16383 16383
heads 16 16
sectors/track 63 63
--
CHS current addressable sectors: 16514064
LBA user addressable sectors: 268435455
LBA48 user addressable sectors: 390721968
Logical Sector size: 512 bytes
Physical Sector size: 512 bytes
device size with M = 1024*1024: 190782 MBytes
device size with M = 1000*1000: 200049 MBytes (200 GB)
cache/buffer size = unknown

lark@lark-Latitude-D630:~$ sudo hdparm -t /dev/sda

/dev/sda:
Timing buffered disk reads: 106 MB in 3.04 seconds = 34.82 MB/sec

Its a 4400 rpm drive, lol! but my old ATA drive is about as fast

[whatthefunk]

Is that HDD powered by a squirrel in a cage? :eek:

It is now, after the upgrade. The gerbil it came with just wasnt cutting it.

[Snowhog]

My old Sony Vaio:

/dev/sda:
 Timing buffered disk reads:  52 MB in  3.07 seconds =  16.95 MB/sec

Do I get a prize?

Is that HDD powered by a squirrel in a cage? :eek:

[oshunluvr]

My old Sony Vaio:

/dev/sda:
 Timing buffered disk reads:  52 MB in  3.07 seconds =  16.95 MB/sec

Do I get a prize?

Dang - that's horrible. I've got a crappy thumb drive that's more than twice as fast as that. I hope you don't have to use that machine very often!

[oshunluvr]

stuart@office:~$ sudo hdparm -t /dev/sda

/dev/sda:
Timing buffered disk reads: 390 MB in 3.01 seconds = 129.73 MB/sec
stuart@office:~$ sudo hdparm -t --direct /dev/sda


/dev/sda:
Timing O_DIRECT disk reads: 388 MB in 3.01 seconds = 128.98 MB/sec

Here's mine for comparison. This is a regular hard drive, although a top-o'-the-line one. Is it odd the invoking --direct actually slowed me down? The SSD Fairy is on it's way right now so next week - things will be a lot speedier!

@Steve: No squeaking here. Have you tried WD-40?

[SecretCode]

Yes, but it will be delivered very slowly!

[whatthefunk]

My old Sony Vaio:

/dev/sda:
 Timing buffered disk reads:  52 MB in  3.07 seconds =  16.95 MB/sec

Do I get a prize?

[SteveRiley]

I used a properly-sized index card as the insulator between the cover and the chips.

But, after liposuctioning my M4, I decided to put it back in my T520. That's because I've decided to make that machine my primary computer. Really, it weighs only about a pound more than the X1, it has a bigger LCD with higher pixel density, and it has a quieter keyboard. The T520 will be my at-home machine, for work and not-work, while I will relegate the X1 purely to the briefcase for travel.

Kubuntu Quantal alpha 3 is installing right now.

[HalationEffect]

Having just read that topic at the thinkpads.com forum, my first thought was "I wonder if there was something you could use instead of scotch tape to insulate the case lid from the SMDs, that just happened to have excellent thermal conductivity..."

If such a thing existed, you could make the entire lid of the Crucial drive into a heat-sink for those SMDs