Re: [Lsf-pc] Linux kernel impact on PostgreSQL performance

Dave Chinner <david@fromorbit.com> writes:
> On Wed, Jan 15, 2014 at 02:29:40PM -0800, Jeff Janes wrote:
>> And most importantly, "Also, please don't freeze up everything else in the
>> process"

> If you hand writeback off to the kernel, then writeback for memory
> reclaim needs to take precedence over "metered writeback". If we are
> low on memory, then cleaning dirty memory quickly to avoid ongoing
> allocation stalls, failures and potentially OOM conditions is far more
> important than anything else.....

I think you're in violent agreement, actually.  Jeff's point is exactly
that we'd rather the checkpoint deadline slid than that the system goes
to hell in a handbasket for lack of I/O cycles.  Here "metered" really
means "do it as a low-priority task".
        regards, tom lane