On Thu 28-09-17 09:02:20, Huang, Ying wrote: > Hi, Michal, > > Michal Hocko <mhocko@xxxxxxxxxx> writes: > > > On Wed 27-09-17 23:10:08, Minchan Kim wrote: > >> On Wed, Sep 27, 2017 at 03:50:34PM +0200, Michal Hocko wrote: > >> > On Wed 27-09-17 22:41:17, Minchan Kim wrote: > >> > > On Wed, Sep 27, 2017 at 03:22:41PM +0200, Michal Hocko wrote: > >> > [...] > >> > > > simply cannot disable swap readahead when page-cluster is 0? > >> > > > >> > > That's was what I want really but Huang want to use two readahead > >> > > algorithms in parallel so he wanted to keep two separated disable > >> > > knobs. > >> > > >> > If it breaks existing and documented behavior then it is a clear > >> > regression and it should be fixed. I do not see why this should be > >> > disputable at all. > >> > >> Indeed but Huang doesn't think so. He has thought it's not a regression. > >> Frankly speaking, I'm really bored of discussing with it. > >> https://marc.info/?l=linux-mm&m=150526413319763&w=2 > > > > Then send a patch explaining why you consider this a regression with > > some numbers backing it and I will happily ack it. > > I still think there may be a performance regression for some users > because of the change of the algorithm and the knobs, and the > performance regression can be resolved via setting the new knob. But I > don't think there will be a functionality regression. Do you agree? I am not sure I understand. One thing is clear though. Your change has introduced a regression as described by Minchan. And that has to be resolved no matter what. You cannot expect users will tweak the system to resolve it or configure their systems in a specific way. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
