I occasionally experience "fork: Cannot allocate memory" errors in
situations where networking load is fairly high (I have rather
busy DNS, SMTP and www caching services on this box, which is
a LX 533 MHz with 512MB RAM), but there is still plenty of memory
available (~150MB, as reported by "free" after subtraction of
buffers/cache), and swap is untouched.
This is basically the same problem I had back in june
( http://www.lib.uaa.alaska.edu/axp-list/archive/1999-06/ ,
thread "fork: Cannot allocate memory" ). With 2.2.7 I had it
every few days or hours; with 2.0.37 every few months, but is
now increasing as load grows and becoming annoying again.
Now I noticed with horror that
# cat /proc/sys/vm/freepages
536 0 804
that is (see /usr/src/linux/Documentation/memory-tuning.txt)
the free_pages_low parameter is zero ; I observe the same in
other alphalinux systems running 2.0.36.
So this 0 is likely to be the reason of my errors:
free_pages_low should probably be about double of min_free_pages,
say the docs.
Now I was wondering where this 0 is coming from, as the same file
also says:
The values selected as boot defaults are the following: For a
machine with n>=8 Megabytes of memory, set min_free_pages = n*2,
free_pages_low = n*3 and free_pages_high = n*4. Machines with
8 Megabytes or less behave as if they had 8 Megabytes.
so at boot time I should have had
1024 1536 2048
and so all three these parameters are falling down. Why?
Anybody else seeing vm parameters falling down?
furio ercolessi
Spin - Trieste
-- To unsubscribe: send e-mail to axp-list-request@redhat.com with 'unsubscribe' as the subject. Do not send it to axp-list@redhat.com
This archive was generated by hypermail version 2a22 on Mon Jan 3 11:15:08 2000 PST
Send any problems or questions about this archive to webmaster@alphalinux.org.