> CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture > being able to hot-remove memory. The main users of page migration such as > sys_move_pages(), sys_migrate_pages() and cpuset process migration are > only beneficial on NUMA so it makes sense. > > As memory compaction will operate within a zone and is useful on both NUMA > and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the > user selects CONFIG_COMPACTION as an option. > > Signed-off-by: Mel Gorman <mel@xxxxxxxxx> > Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> > Reviewed-by: Rik van Riel <riel@xxxxxxxxxx> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > --- > mm/Kconfig | 20 ++++++++++++++++---- > 1 files changed, 16 insertions(+), 4 deletions(-) > > diff --git a/mm/Kconfig b/mm/Kconfig > index 9c61158..04e241b 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -172,17 +172,29 @@ config SPLIT_PTLOCK_CPUS > default "4" > > # > +# support for memory compaction > +config COMPACTION > + bool "Allow for memory compaction" > + def_bool y > + select MIGRATION > + depends on EXPERIMENTAL && HUGETLBFS && MMU > + help > + Allows the compaction of memory for the allocation of huge pages. > + If select MIGRATION works, we can remove "depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE" line from config MIGRATION. > +# > # support for page migration > # > config MIGRATION > bool "Page migration" > def_bool y > - depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE > + depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION > help > Allows the migration of the physical location of pages of processes > - while the virtual addresses are not changed. This is useful for > - example on NUMA systems to put pages nearer to the processors accessing > - the page. > + while the virtual addresses are not changed. This is useful in > + two situations. The first is on NUMA systems to put pages nearer > + to the processors accessing. The second is when allocating huge > + pages as migration can relocate pages to satisfy a huge page > + allocation instead of reclaiming. > > config PHYS_ADDR_T_64BIT > def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT > -- > 1.6.5 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>