On Fri, 12 Jul 2019 13:39:35 +0100 Mel Gorman <mgorman@xxxxxxx> wrote: > > So although I still think that just failing the migration if we cannot > > invalidate buffer heads is a safer choice, just extending the private_lock > > protected section does not seem as bad as I was afraid. > > > > That does not seem too bad and your revised patch looks functionally > fine. I'd leave out the tracepoints though because a perf probe would have > got roughly the same data and the tracepoint may be too specific to track > another class of problem. Whether the tracepoint survives or not and > with a changelog added; > > Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> > > Andrew, which version do you want to go with, the original version or > this one that holds private_lock for slightly longer during migration? The revised version looks much more appealing for a -stable backport. I expect any mild performance issues can be address in the usual fashion. My main concern is not to put a large performance regression into mainline and stable kernels. How confident are we that this is (will be) sufficiently tested from that point of view?