Hi, 2010/1/17 Craig Small <csm...@debian.org>: > On Sat, Jan 16, 2010 at 04:41:35PM +0100, Nicolas Parpandet wrote: >> The "free" cmd does not show properly used memory, as you can see, >> slab is not taken into account, "used / buffer cache" is a useless >> information, > Hello, > > It's a big call to say "not show properly" with anything at all to do > with Linux memory management. The problem is that nothing is defined > that well. > >> for instance on this server : >> r...@vzb:/etc/apt# free >> total used free shared buffers cached >> Mem: 33086568 137060 32949508 0 412 5468 >> -/+ buffers/cache: 131180 32955388 > [...] >> Mem: 33086568 2664080 30422488 0 896132 24184 >> -/+ buffers/cache: 1743764 31342804 > Both of these sets of figures add up. I'm finding it difficult to work > out which number you are having a problem with.
In fact these two records shows differents memory usage, but there was nothing different but slab cache usage (after the find/updatedb with a scan of all the filesystem). This kind of memory usage does not reflect user point of view, because as soon as a program request memory, slab cache is reduced and this memory can be used for userspace programs. >> I may be necessary to substract slab usage from used col on the +/- buffer >> cache row. > Are you saying that buffers is not just buffers but buffers plus > something else (say slab usage)? Yes ! exact, that's what I am saying. You can monitor slab usage in /proc/meminfo or with the "slabtop" command, but "free" does not take into account the slab cache. > If so, you will need to talk to the kernel folk, because it comes > directly from the kernel (grep 'Buffers:' /proc/meminfo). free just > prints what it gets. I don't know what to do, the user point of view (me and others, for instance https://bugs.launchpad.net/ubuntu/+source/procps/+bug/126329 ) is the free command doesnt reflect any more the memory used by programs, I cannot say if the answer is changing the kernel /proc interface or modifing userland "free" Regards Nicolas > > - Craig > -- > Craig Small GnuPG:1C1B D893 1418 2AF4 45EE 95CB C76C E5AC 12CA DFA5 > http://www.enc.com.au/ csmall at : enc.com.au > http://www.debian.org/ Debian GNU/Linux, software should be Free > -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
