Am 09.07.2015 um 19:16 schrieb Michael MacIsaac: > I'm going to stop here for now. I've learned a lot about Linux memory from > this thread (but that's easy when you don't know much to begin with :)). > > I guess a question to the Linux developers in Germany would be: > > If vmcp is called with a buffer of 1M and the last slab in /proc/buddyinfo > is 0, would it not be reasonable to nudge the kernel to free at least one > slot up, assuming this can be done safely?
That does not help. The kernel frees up memory when needed (or when below a watermark). So the AS-IS state does not tell you anything. Now: newer kernels (those that offer transparent hugepages) do have memory compaction which tries to reorganize memory on pressure, so this case should be less of an issue. Anothing thing: 1M is quite large (the larges contiguous memory that Linux wants to allocate as slab). So try to not use that unless you need it. If you want to know how much memory is needed, then vmcp gives you back the result of the diagnose: # vmcp q dasd all [...] Error: output (74764 bytes) was truncated, try --buffer to increase size # vmcp --buffer 75000 q dasd all [...] # Christian ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
