time cat /proc/*/statm ?

Hi,

Is it reasonable for a 64bit dual cpu to take 5+ seconds of processing to cat /proc/*/statm when there is hardly more than 1gb of actual memory space used by processes (the rest being filesystem cache)?

This makes top or anything else that uses statm, unusable.

I don't observe this behavior on a 4gb 32bit machine, with the same working set of mysqld processes, and 3gb of filesystem cache.

# free
             total       used       free     shared    buffers     cached
Mem:      16278356   16264484      13872          0      85400   14819932
-/+ buffers/cache:    1359152   14919204

# ps -eda|wc
 216     866    6751

# time cat /proc/*/statm
:
:
:
real    0m5.740s
user    0m0.003s
sys     0m5.521s

# uname -a

Linux silver 2.4.21-151-smp #22 SMP Mon Jan 5 21:31:07 PST 2004 x86_64 x86_64 x86_64 GNU/Linux

thanks!!

Why does top still read /proc/*/statm anyway? It's not as if top actually ever used that information (the top I looked at at the time, that is). I submitted a patch a few months ago to remove statm because it is a) broken and b) redundant. The message containing detailed reasoning should be in the linux-mm archives.

Roger

Here on alpha, it takes 0.023s (0.011 sys) for 58 processes on 2.4.23. Perhaps there's something specific to x86_64 ?

Willy