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Dear friends:
Thanks every much for your kindness, my
questions were gradually solved here.
Now I can use fseeko64() now, but in fact it
takes very long time
for a fseeko64() call as if the call is suspended. During the
call,
kswapd use CPU madly, statistics as follows:
2:30pm up 3:17, 4 users, load
average: 0.23, 0.05, 0.02
45 processes: 41 sleeping, 4 running, 0 zombie, 0
stopped
CPU states: 1.9% user, 98.0% system, 0.0% nice,
0.0% idle
Mem: 126104K av, 123992K used,
2112K free, 0K shrd, 6780K
buff
Swap: 56188K av, 0K
used, 56188K
free
98704K cached
PID USER PRI NI
SIZE RSS SHARE STAT LIB %CPU %MEM TIME
COMMAND
3 root
17 0 0
0 0 RW 0 90.0
0.0 3:12 kswapd
2112
root 9 0 428
428 304 R 0 6.7
0.3 0:00 a.out
2113 root
12 0 872 872 684
R 0 3.8 0.6 0:00
top
1 root
8 0 476 476 404
S 0 0.0 0.3 0:05
init
2 root
9 0 0
0 0 SW 0 0.0
0.0 0:00 kapmd
4
root 9 0
0 0 0 SW
0 0.0 0.0 0:00 kflushd
5
root 9 0
0 0 0 SW
0 0.0 0.0 0:03 kupdate
6
root -1 -20
0 0 0 SW<
0 0.0 0.0 0:00 mdrecoveryd
19
root 9 0 548
548 452 S 0 0.0
0.4 0:00 devfsd
1028
root 9 0
0 0 0 SW
0 0.0 0.0 0:00 pagebuf_daemon
1029
root 9 0
0 0 0 SW
0 0.0 0.0 0:00 page_daemon
1291
bin 9 0
496 496 404 S 0
0.0 0.3 0:00 portmap
1291
bin 9 0
496 496 404 S 0
0.0 0.3 0:00 portmap
1314
root 9 0 560
560 472 S 0 0.0
0.4 0:00 rpc.statd
1328
root 9 0 480
480 412 S 0 0.0
0.3 0:00 apmd
1384 root
9 0 552 552 452
S 0 0.0 0.4 0:00
syslogd
1393 root 9
0 1080 1080 388 S 0
0.0 0.8 0:00 klogd
1407
nobody 9 0 628
628 520 S 0 0.0
0.4 0:00 identd
a.out is my test program,
which opens a big file(4.7G) on xfs filesystem
by using fopen64(); and then use
fseeko64() to locate to 2.1G. The statistics
is got when the program executing fseeko64(), it took more
than 2 minutes. After
2 minutes, the call return successfully.
My questions are:
why it took so many time
for a seek call? I'v never met it on ext2 or xfs
on IRIX.
why kswapd ate all my CPU
resource and memory resource when I call fseeko64()?
My destination is to use
big files in my program, open/read/seek, very simple
needs, but how can I do this?
Thanks a lot!
yangxy.
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