On Fri, Sep 05, 2014 at 12:23:26PM +0300, Andriy Gapon wrote: > on 04/09/2014 04:18 Steven Hartland said the following: > > Indeed that would be interesting, but we might find that its quite memory > > size > > dependent given the scaling so confirming HW details would be nice too. > > > > I'd also be interested to know who wins the free race between the VM and ARC > > when using that value. > > BTW, I've written a small silly program that tests for a problem that affected > me in the distant past: http://people.freebsd.org/~avg/arc-vs-swap.c > > It gobbles almost all of the memory and then just sits on it never accessing > it > again. At the same time it repeatedly reads blocks of data from a large file. > The idea is that eventually the unused memory should be pushed out to the swap > and the ARC is allowed to grow to accommodate for the data being read. > > I run this program on a freshly booted system without any other applications. > Prior to r270759 the system behaves as expected. Although the pace of > shifting > balance between the ARC and the swap-backed pages is quite slow. > After r270759 and with the default tuning the ARC always sits at its minimum > size. To me this is a regression. > > To summarize: I really appreciate the improvements that you are making here > https://reviews.freebsd.org/D702 > Thanks! > > P.S. > I wish there was an easy way to make the page cache and the ARC aware of each > other.
I think no single way for any workload. For some workloads ARC is prefered. For some -- RSS is prefered. May be need some tunable for elastics factor ARC/RSS? PS: very bad that 'data limit' don't anymore reflect application memory consumer. and very small application can adapt to 'no memory' from system. _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
