Messages in this thread | | | Date | Mon, 25 Jul 2005 17:24:26 +0200 | From | Willy Tarreau <> | Subject | Re: Problem with Asus P4C800-DX and P4 -Northwood- |
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On Mon, Jul 25, 2005 at 03:10:08PM +0200, Andreas Baer wrote: (...) > I have (S-ATA-150 Disk 80GB) > > /dev/sda: 50.59 MB/sec > /dev/sda1: 50.62 MB/sec (Windows FAT32) > /dev/sda6: 41.63 MB/sec (Linux ReiserFS) > > On the Notebook I have at most an ATA-100 Disk with 80GB and it shows the > same declension. > > Here I have > > /dev/hda: 26.91 MB/sec > /dev/hda1: 26.90 MB/sec (Windows FAT32) > /dev/hda7: 17.89 MB/sec (Linux EXT3) > > Could you give me a reason how this is possible?
a reason for what ? the fact that the notebook performs faster than the desktop while slower on I/O ?
> Vmstat for Notebook P4 3.0 GHz 512 MB RAM:
Your Notebook's P4 has HT enabled (50% apparent idle remain permanently during operation). But you'll note that your load is 60% system + 40% user there, and that you do absolutely no I/O (I presume it's the second run and it's cached).
> procs -----------memory---------- ---swap-- -----io---- --system-- > ----cpu---- > r b swpd free buff cache si so bi bo in cs us sy > id wa > 1 0 0 179620 14812 228832 0 0 33 21 557 184 3 1 > 95 1 > 2 0 0 178828 14812 228832 0 0 0 0 1295 819 6 2 > 92 0 > 1 0 0 175948 14812 228832 0 0 0 0 1090 111 37 17 > 46 0 > 1 0 0 175948 14812 228832 0 0 0 0 1064 101 23 28 > 50 0 > 1 0 0 175948 14812 228832 0 0 0 0 1066 100 20 31 > 49 0 > 1 0 0 175980 14820 228824 0 0 0 48 1066 119 20 30 > 50 0 > 1 0 0 175980 14820 228824 0 0 0 0 1067 86 19 31 > 50 0 > 1 0 0 175988 14820 228824 0 0 0 0 1064 115 20 30 > 50 0
(...)
> Vmstat for Desktop P4 2.4 GHz 1024 MB RAM:
This one's hyperthreaded too (apparent consumption never goes above 50%). However, while not doing any I/O either, you're always spending only 4% in user and 96% in system. This means that it might take 10x more time to complete the same operations, had it been user-cpu bound. And this is about what you observe.
There clearly is a problem on the system installed on this machine. You should use strace to see what this machine does all the time, it is absolutely not expected that the user/system ratios change so much between two nearly identical systems. So there are system calls which eat all CPU. You may want to try strace -Tttt on the running process during a few tens of seconds. I guess you'll immediately find the culprit amongst the syscalls, and it might give you a clue.
> procs -----------memory---------- ---swap-- -----io---- --system-- > ----cpu---- > r b swpd free buff cache si so bi bo in cs us sy > id wa > 1 0 0 594688 39340 292228 0 0 52 29 581 484 5 2 > 92 2 > 1 0 0 591208 39340 292228 0 0 0 68 1116 545 15 14 > 71 0 > 1 0 0 591208 39340 292228 0 0 0 0 1090 112 3 48 > 50 0 > 1 0 0 591208 39340 292228 0 0 0 0 1089 124 2 48 > 50 0 > 1 0 0 591208 39340 292228 0 0 0 0 1089 114 3 48 > 50 0 > 1 0 0 591208 39340 292228 0 0 0 0 1090 120 1 49 > 50 0 > 1 0 0 591208 39340 292228 0 0 0 24 1094 138 2 49 > 50 0 > 1 0 0 591256 39340 292228 0 0 0 0 1090 118 2 48 > 50 0
(...)
Regards, Willy
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