Hi Wanpeng, On 2013/9/5 10:11, Wanpeng Li wrote: > Hi Jianguo, > On Wed, Sep 04, 2013 at 09:30:22PM +0800, Jianguo Wu wrote: >> Since commit d39d33c332(thp: enable direct defrag), defrag is enable >> for all transparent hugepage page faults by default, not only in >> MADV_HUGEPAGE regions. >> >> Signed-off-by: Jianguo Wu <wujianguo@xxxxxxxxxx> >> --- >> mm/huge_memory.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index a92012a..abf047e 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -28,10 +28,8 @@ >> >> /* >> * By default transparent hugepage support is enabled for all mappings > > This is also stale. TRANSPARENT_HUGEPAGE_ALWAYS is not configured by default in > order that avoid to risk increase the memory footprint of applications w/o a > guaranteed benefit. > Right, how about this: By default transparent hugepage support is disabled in order that avoid to risk increase the memory footprint of applications w/o a guaranteed benefit, and khugepaged scans all mappings when transparent hugepage enabled. Defrag is invoked by khugepaged hugepage allocations and by page faults for all hugepage allocations. Thanks, Jianguo Wu > Regards, > Wanpeng Li > >> - * and khugepaged scans all mappings. Defrag is only invoked by >> - * khugepaged hugepage allocations and by page faults inside >> - * MADV_HUGEPAGE regions to avoid the risk of slowing down short lived >> - * allocations. >> + * and khugepaged scans all mappings. Defrag is invoked by khugepaged >> + * hugepage allocations and by page faults for all hugepage allocations. >> */ >> unsigned long transparent_hugepage_flags __read_mostly = >> #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS >> -- >> 1.8.1.2 >> >> -- >> 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> > > -- > 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> > > -- 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>