| 1 |
J. Roeleveld writes: |
| 2 |
|
| 3 |
> On Wednesday 25 August 2010 03:32:40 Alex Schuster wrote: |
| 4 |
|
| 5 |
> > I have an AMD Athlon(tm) Dual Core Processor 4850e CPU, on-board |
| 6 |
> > Radeon HD 3200 graphics, 4GB of memory, an 1.5 TB drive. Lots of LVM |
| 7 |
> > volumes, all encrypted, except for /usr/src and portage stuff. The |
| 8 |
> > system is ~amd64, and I have -march=k8-sse3 in my CFLAGS. Current |
| 9 |
> > kernel is 2.6.34-tuxonice, but I also tried others. I'm running KDE4 |
| 10 |
> > with desktop effects enabled, X itself takes about 30-40% of CPU |
| 11 |
> > time according to top. After system startup and login into KDE, 3.5G |
| 12 |
> > of RAM are occupied. This increases after a while, and I need swap |
| 13 |
> > space. Nothing to worry about I think. |
| 14 |
> |
| 15 |
> Encrypted filesystems can cause additional with activity, but I would |
| 16 |
> expect that to remain the same over a long period. |
| 17 |
|
| 18 |
And I just moved my PORTAGE_TMPDIR to an unencrypted partition. |
| 19 |
Can LVM create noticeable overhead? I also resized my logical volumes a |
| 20 |
couple of times, could this lead to some LVM fragmentation? |
| 21 |
|
| 22 |
> However, how is the write and read performance on those disks? |
| 23 |
|
| 24 |
Here's the output of hdparm -t for all drives, 4 times. |
| 25 |
|
| 26 |
/dev/sda: (SATA system drive) |
| 27 |
Timing buffered disk reads: 118 MB in 3.08 seconds = 38.37 MB/sec |
| 28 |
Timing buffered disk reads: 194 MB in 3.11 seconds = 62.47 MB/sec |
| 29 |
Timing buffered disk reads: 322 MB in 3.01 seconds = 106.82 MB/sec |
| 30 |
Timing buffered disk reads: 244 MB in 3.00 seconds = 81.21 MB/sec |
| 31 |
|
| 32 |
/dev/sdb: (PATA master) |
| 33 |
Timing buffered disk reads: 114 MB in 3.02 seconds = 37.70 MB/sec |
| 34 |
Timing buffered disk reads: 114 MB in 3.00 seconds = 37.97 MB/sec |
| 35 |
Timing buffered disk reads: 116 MB in 3.05 seconds = 38.06 MB/sec |
| 36 |
Timing buffered disk reads: 116 MB in 3.05 seconds = 38.07 MB/sec |
| 37 |
|
| 38 |
/dev/sdc: (PATA slave) |
| 39 |
Timing buffered disk reads: 164 MB in 3.03 seconds = 54.21 MB/sec |
| 40 |
Timing buffered disk reads: 166 MB in 3.02 seconds = 55.04 MB/sec |
| 41 |
Timing buffered disk reads: 166 MB in 3.01 seconds = 55.10 MB/sec |
| 42 |
Timing buffered disk reads: 158 MB in 3.01 seconds = 52.41 MB/sec |
| 43 |
|
| 44 |
/dev/sdd: (SATA backup drive) |
| 45 |
Timing buffered disk reads: 314 MB in 3.00 seconds = 104.55 MB/sec |
| 46 |
Timing buffered disk reads: 312 MB in 3.01 seconds = 103.67 MB/sec |
| 47 |
Timing buffered disk reads: 308 MB in 3.01 seconds = 102.34 MB/sec |
| 48 |
Timing buffered disk reads: 314 MB in 3.00 seconds = 104.60 MB/sec |
| 49 |
|
| 50 |
The system drive throughput varies a lot, depending on other I/O. |
| 51 |
|
| 52 |
I |
| 53 |
|
| 54 |
|
| 55 |
> You're running KDE4, guess you went for the default and use mysql for |
| 56 |
> "app- office/akonadi-server". |
| 57 |
> |
| 58 |
> I switched to using "sqlite" for this due to issues getting it to work |
| 59 |
> with mysql. I think this might help there? |
| 60 |
|
| 61 |
So I only have to set the sqlite use flag and remove the mysql use flag |
| 62 |
for akonadi-server? I'm doing this now. And this also gives an example for |
| 63 |
what is going on here: |
| 64 |
|
| 65 |
I have just logged into KDE. I did not log out since yesterday, and when |
| 66 |
started a VM with vmplayer, the system swapped like crazy, I could not use |
| 67 |
it for minutes. After this, the panel did not react any more, and the |
| 68 |
desktop background did not redraw, so I logged out and in again. The VM |
| 69 |
started fine now. Well, could be faster, but maybe it was okay. |
| 70 |
Then I started answering your mail, and tried to reemerge akonadi-server, |
| 71 |
but I had a type, so portage took a long search for akomadi-server. |
| 72 |
meanwhile the dektop became quite unresponsive, load went high, and I made |
| 73 |
a screenshot [*]. If you look at the top right, gkrellm shows this above |
| 74 |
'Proc'. The first increase at the left was after I started emerge, the 2nd |
| 75 |
at the right was after I pressed the PrtSc key. |
| 76 |
|
| 77 |
|
| 78 |
> > Performance does not feel too bad at first. But after a while, I |
| 79 |
> > cannot even play videos during emerges. The playback stutters, |
| 80 |
> > sometimes I have pauses for several seconds. As long as there is no |
| 81 |
> > swap space occpied, it's not so bad I think. Maybe I have a probelm |
| 82 |
> > with disk I/O, and things get much worse when swapping occurs. When |
| 83 |
> > I look at iotop, I see various programs like chromium and various |
| 84 |
> > KDE applications appear. I guess that's normal, but should not be |
| 85 |
> > noticeable. Hey, there were times when I created a 2G tmpfs for |
| 86 |
> > /var/tmp/portage, with only 3G on my 32bit system. BTW, I lowered my |
| 87 |
> > swappiness to 10. This helps a little I think, because the swapping |
| 88 |
> > occurs later, the system is more responsive. |
| 89 |
> |
| 90 |
> Do you also encrypt swap? |
| 91 |
|
| 92 |
Yes. |
| 93 |
|
| 94 |
> Disk I/O is, in my experience, a very common cause for "freeze-ups". |
| 95 |
> Can you test with unencrypted disks to see if the issue occurs then as |
| 96 |
> well? |
| 97 |
|
| 98 |
Yes, I can do this. It's some work, but I tried so much, why not this. I |
| 99 |
have some free space, and already have written a backup script that |
| 100 |
automatically creates LVM snapshots, decrypts them, and backs it up, so I |
| 101 |
can do this from the running system. |
| 102 |
|
| 103 |
|
| 104 |
> > And I have similar problems when copying data between some old PATA |
| 105 |
> > drives. When I copy stuff and do a mkfs on another partition, mplayer |
| 106 |
> > sometimes stutters and hangs for ten seconds. No joy. Working with |
| 107 |
> > KDE sucks, switching dektops sometimes takes ages, and even now I am |
| 108 |
> > typing faster than kmail can display the characters. That's with am |
| 109 |
> > emerge of chromium running, with PORTAGE_NICENESS=10 and using |
| 110 |
> > ionice -c 3. Load is around 8, but sometimes gets even higher. And |
| 111 |
> > then, load suddenly drops back to lower values, as if somthing was |
| 112 |
> > blocking. Some applications swapping, maybe. |
| 113 |
> |
| 114 |
> Very possibly, maybe an idea to check which applications are hogging |
| 115 |
> the memory. If it is the swapping of the system, then this will be |
| 116 |
> caused by the most memory-hungry processes. |
| 117 |
> |
| 118 |
> Can you post the result of: "ps axu"? |
| 119 |
> This will give an indication which processes are running and using a |
| 120 |
> lot of memory. |
| 121 |
|
| 122 |
First, here is free -m: |
| 123 |
total used free shared buffers cached |
| 124 |
Mem: 3452 3225 226 0 54 325 |
| 125 |
-/+ buffers/cache: 2844 607 |
| 126 |
Swap: 4094 935 3159 |
| 127 |
|
| 128 |
And here the output of top, sorted by memory. I think it is a similar |
| 129 |
output to ps axu, but more condensed and better readable via mail. The |
| 130 |
full ps aux output, sorted by memory, is in [2]. |
| 131 |
|
| 132 |
top - 21:23:03 up 1 day, 7 min, 11 users, load average: 0.04, 0.05, 0.02 |
| 133 |
Tasks: 418 total, 1 running, 417 sleeping, 0 stopped, 0 zombie |
| 134 |
Cpu(s): 17.8%us, 12.7%sy, 9.9%ni, 45.9%id, 13.5%wa, 0.1%hi, 0.1%si, 0.0%st |
| 135 |
Mem: 3534936k total, 3312312k used, 222624k free, 56264k buffers |
| 136 |
Swap: 4193272k total, 957908k used, 3235364k free, 334048k cached |
| 137 |
|
| 138 |
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND |
| 139 |
25993 root 20 0 847m 475m 47m S 21 13.8 49:01.11 X |
| 140 |
26553 wonko 20 0 1312m 235m 10m S 0 6.8 0:28.32 java |
| 141 |
26925 wonko 20 0 698m 112m 18m S 0 3.2 3:30.75 kontact |
| 142 |
26961 wonko 20 0 526m 79m 13m S 0 2.3 2:16.01 chrome |
| 143 |
26566 wonko 20 0 1128m 72m 10m S 0 2.1 1:02.46 amarok |
| 144 |
27056 wonko 20 0 871m 57m 19m S 0 1.7 0:05.07 chrome |
| 145 |
30324 root 30 10 195m 55m 1136 S 0 1.6 0:09.46 emerge |
| 146 |
27051 wonko 20 0 874m 50m 8668 S 0 1.5 0:14.16 chrome |
| 147 |
26126 wonko 20 0 1028m 44m 11m S 2 1.3 9:18.94 plasma-desktop |
| 148 |
27046 wonko 20 0 878m 41m 7324 S 0 1.2 0:16.59 chrome |
| 149 |
27122 wonko 20 0 871m 36m 7660 S 0 1.0 0:40.03 chrome |
| 150 |
27036 wonko 20 0 865m 29m 7492 S 0 0.8 0:00.94 chrome |
| 151 |
27198 wonko 20 0 860m 28m 6240 S 0 0.8 0:04.76 chrome |
| 152 |
26101 wonko 20 0 427m 28m 8672 S 4 0.8 5:27.48 kwin |
| 153 |
26298 wonko 20 0 396m 26m 9.9m S 0 0.8 0:02.91 knotes |
| 154 |
27766 wonko 20 0 857m 26m 5924 S 0 0.8 0:03.03 chrome |
| 155 |
26903 root 20 0 64316 25m 288 S 0 0.7 0:00.33 screen |
| 156 |
27203 wonko 20 0 865m 24m 5960 S 0 0.7 0:04.06 chrome |
| 157 |
30226 wonko 20 0 367m 23m 9232 S 0 0.7 0:03.21 gwenview |
| 158 |
26221 wonko 20 0 609m 23m 3752 S 0 0.7 0:02.55 knotify4 |
| 159 |
|
| 160 |
X takes an awful lot, then comes java, which is running only for my |
| 161 |
tvbrowser. And many many chrome processes. |
| 162 |
|
| 163 |
> > Now I am out of ideas. I really hope someone here has one. I cannot |
| 164 |
> > work with this system any more when emerges are going on. |
| 165 |
> |
| 166 |
> Had similar issues with a desktop machine myself, managed to kill some |
| 167 |
> "features" that I wasn't using and this solved most of the problems. |
| 168 |
|
| 169 |
I hope I can say this soon, too. |
| 170 |
|
| 171 |
> Lets see where checking for IO-speeds and memory-usage of your apps |
| 172 |
> take us :) |
| 173 |
|
| 174 |
Thanks for your help! I appreciate this very much. |
| 175 |
|
| 176 |
Wonko |
| 177 |
|
| 178 |
[1] http://www.wonkology.org/comp/desktop/2010-08-25_emerge-akomadi.png |
| 179 |
[2] http://www.wonkology.org/gentoo/ |
Archives
