Thank you for your attention to this matter. >> Are there still some methods that could be used by the Linux kernel >> to reduce memory fragmentation while both CONFIG-MIGRATION >> and CONFIG-COMPACTION are disabled? > > >We do have mobility grouping on pageblock order. >Also, I think you can use ZONE_MOVABLE without migration and compaction, >to at least locally limit unmovable fragmentation. It's a good news. Could you please explain that in more detail for me or suggest some documents for me to go through. As per the post(http://lkml.iu.edu/hypermail/linux/kernel/1703.1/06782.html), I think it's something like ZONE_NORMAL. And I find that "ZONE_MOVEABLE" is available on Linux-v4.9. >> >> Are there some system settings that could make for this goal? > >Why don't you want page compaction/migration? Because I am using a real-time system(and I have to apply a patch to Linux kernel), I have no choice other than disabling these aforementioned options. Is there some potential problems that I should be aware of if I enable "ZONE_MOVABLE" on real-time system? Best Regards. David Hildenbrand <david@xxxxxxxxxx> 于2020年6月24日周三 下午5:53写道： > > On 23.06.20 17:52, 孙世龙 sunshilong wrote: > > Are there still some methods that could be used by the Linux kernel > > to reduce memory fragmentation while both CONFIG-MIGRATION > > and CONFIG-COMPACTION are disabled? > > We do have mobility grouping on pageblock order. > > Also, I think you can use ZONE_MOVABLE without migration and compaction, > to at least locally limit unmovable fragmentation. > > > > > Are there some system settings that could make for this goal? > > Why don't you want page compaction/migration? > > -- > Thanks, > > David / dhildenb >
