Re: vmstat's entries type

From: <sthaug_at_nethelp.no>
Date: Sun, 23 Jul 2006 20:57:59 +0200 (CEST)
> > One approach that we could use for 64-bit counters would be to just
> > use 32-bits one, and poll them for overflow and bump an overflow
> > count.  This assumes that the 32-bit counters overflow much less often
> > than the polling interval, and easily triples the amount of storage
> > for each of them...  It is ugly :-(
> > 
> 
> What's wrong with the add+adc (asm) approach found on any i386?

Presumably the fact that add + adc isn't an atomic operation. So if
you want to guarantee 64 bit consistency, you need locking or similar.

Steinar Haug, Nethelp consulting, sthaug_at_nethelp.no
Received on Sun Jul 23 2006 - 16:58:05 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:58 UTC