Messages in this thread | | | Subject | Re: [PATCH 2/2] mm/dax: Don't enable huge dax mapping by default | From | "Aneesh Kumar K.V" <> | Date | Wed, 6 Mar 2019 18:15:25 +0530 |
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On 3/6/19 5:14 PM, Michal Suchánek wrote: > On Wed, 06 Mar 2019 14:47:33 +0530 > "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> wrote: > >> Dan Williams <dan.j.williams@intel.com> writes: >> >>> On Thu, Feb 28, 2019 at 1:40 AM Oliver <oohall@gmail.com> wrote: >>>> >>>> On Thu, Feb 28, 2019 at 7:35 PM Aneesh Kumar K.V >>>> <aneesh.kumar@linux.ibm.com> wrote: > >> Also even if the user decided to not use THP, by >> echo "never" > transparent_hugepage/enabled , we should continue to map >> dax fault using huge page on platforms that can support huge pages. > > Is this a good idea? > > This knob is there for a reason. In some situations having huge pages > can severely impact performance of the system (due to host-guest > interaction or whatever) and the ability to really turn off all THP > would be important in those cases, right? >
My understanding was that is not true for dax pages? These are not regular memory that got allocated. They are allocated out of /dev/dax/ or /dev/pmem*. Do we have a reason not to use hugepages for mapping pages in that case?
-aneesh
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