Hi Jianguo, On Thu, Sep 05, 2013 at 11:54:00AM +0800, Jianguo Wu wrote: >On 2013/9/5 11:37, Wanpeng Li wrote: > >> On Thu, Sep 05, 2013 at 11:04:22AM +0800, Jianguo Wu wrote: >>> 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 >> >> I don't think it's disabled. TRANSPARENT_HUGEPAGE_MADVISE is configured >> by default. >> > >Hi Wanpeng, > >We have TRANSPARENT_HUGEPAGE and TRANSPARENT_HUGEPAGE_ALWAYS/TRANSPARENT_HUGEPAGE_MADVISE, >TRANSPARENT_HUGEPAGE_ALWAYS or TRANSPARENT_HUGEPAGE_MADVISE is configured only if TRANSPARENT_HUGEPAGE >is configured. > >By default, TRANSPARENT_HUGEPAGE=n, and TRANSPARENT_HUGEPAGE_ALWAYS is configured when TRANSPARENT_HUGEPAGE=y. > >commit 13ece886d9(thp: transparent hugepage config choice): > > config TRANSPARENT_HUGEPAGE >- bool "Transparent Hugepage Support" if EMBEDDED >+ bool "Transparent Hugepage Support" > depends on X86 && MMU >- default y > >+choice >+ prompt "Transparent Hugepage Support sysfs defaults" >+ depends on TRANSPARENT_HUGEPAGE >+ default TRANSPARENT_HUGEPAGE_ALWAYS > mmotm tree: grep 'TRANSPARENT_HUGEPAGE' .config CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE=y # CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS is not set CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y distro: grep 'TRANSPARENT_HUGEPAGE' config-3.8.0-26-generic CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE=y # CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS is not set CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y >Thanks, >Jianguo Wu > >> Regards, >> Wanpeng Li >> >>> 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>