On Mon 26-06-17 08:28:07, Alkis Georgopoulos wrote: > Στις 23/06/2017 02:38 μμ, ο Michal Hocko έγραψε: > >this means that the highmem is not dirtyable and so only 20% of the free > >lowmem (+ page cache in that region) is considered and writers might > >get throttled quite early (this might be a really low number when the > >lowmem is congested already). Do you see the same problem when enabling > >highmem_is_dirtyable = 1? > > > > Excellent advice! :) > Indeed, setting highmem_is_dirtyable=1 completely eliminates the issue! > > Is that something that should be =1 by default, Unfortunatelly, this is not something that can be applied in general. This can lead to a premature OOM killer invocations. E.g. a direct write to the block device cannot use highmem, yet there won't be anything to throttle those writes properly. Unfortunately, our documentation is silent about this setting. I will post a patch later. -- 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>
