On Thu 06-07-17 07:16:49, Wei Yang wrote: > On Fri, Jun 30, 2017 at 01:01:18PM +0200, Michal Hocko wrote: > >On Fri 30-06-17 11:55:45, Michal Hocko wrote: > >> On Fri 30-06-17 17:39:56, Wei Yang wrote: > >> > On Fri, Jun 30, 2017 at 4:39 PM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > >> [...] > >> > > yes and to be honest I do not plan to fix it unless somebody has a real > >> > > life usecase for it. Now that we allow explicit onlininig type anywhere > >> > > it seems like a reasonable behavior and this will allow us to remove > >> > > quite some code which is always a good deal wrt longterm maintenance. > >> > > > >> > > >> > hmm... the statistics displayed in /proc/zoneinfo would be meaningless > >> > for zone_normal and zone_movable. > >> > >> Why would they be meaningless? Counters will always reflect the actual > >> use - if not then it is a bug. And wrt to zone description what is > >> meaningless about > >> memory34/valid_zones:Normal > >> memory35/valid_zones:Normal Movable > >> memory36/valid_zones:Movable > >> memory37/valid_zones:Movable Normal > >> memory38/valid_zones:Movable Normal > >> memory39/valid_zones:Movable Normal > >> memory40/valid_zones:Normal > >> memory41/valid_zones:Movable > >> > >> And > >> Node 1, zone Normal > >> pages free 65465 > >> min 156 > >> low 221 > >> high 286 > >> spanned 229376 > >> present 65536 > >> managed 65536 > >> [...] > >> start_pfn: 1114112 > >> Node 1, zone Movable > >> pages free 65443 > >> min 156 > >> low 221 > >> high 286 > >> spanned 196608 > >> present 65536 > >> managed 65536 > >> [...] > >> start_pfn: 1179648 > >> > >> ranges are clearly defined as [start_pfn, start_pfn+managed] and managed > > > >errr, this should be [start_pfn, start_pfn + spanned] of course. > > > > The spanned is not adjusted after offline, neither does start_pfn. For example, > even offline all the movable_zone range, we can still see the spanned. Which is completely valid. Offline only changes present/managed. > Below is a result with a little changed kernel to show the start_pfn always. > The sequence is: > 1. bootup > > Node 0, zone Movable > spanned 65536 > present 0 > managed 0 > start_pfn: 0 > > 2. online movable 2 continuous memory_blocks > > Node 0, zone Movable > spanned 65536 > present 65536 > managed 65536 > start_pfn: 1310720 > > 3. offline 2nd memory_blocks > > Node 0, zone Movable > spanned 65536 > present 32768 > managed 32768 > start_pfn: 1310720 > > 4. offline 1st memory_blocks > > Node 0, zone Movable > spanned 65536 > present 0 > managed 0 > start_pfn: 1310720 > > So I am not sure this is still clearly defined? Could you be more specific what is not clearly defined? You have offlined all online memory blocks so present/managed is 0 while the spanned is unchanged because the zone is still defined in range [1310720, 1376256]. I also do not see how this is related with the discussed patch as there is no zone interleaving involved. -- 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>
