>>In my benchmarks, THP increase the memory transaction speed by 5-10% in the >>KVM guest if THP is activated on the host side, not in the VM side. I know >>that THP for databases is bad, but we are not using THP in the guest >>where >>the database lives. Can someone provide some benchmarks for that case or >>further information? Any suggestions?
Oh, good to known. How much memory do you use it your vm ? what is the database software ? ----- Mail original ----- De: "Andreas Steinel" <a.stei...@gmail.com> À: "Daniel Hunsaker" <danhunsa...@gmail.com> Cc: "aderumier" <aderum...@odiso.com>, "dietmar" <diet...@proxmox.com>, "pve-devel" <pve-devel@pve.proxmox.com> Envoyé: Mercredi 9 Septembre 2015 16:32:23 Objet: Re: [pve-devel] disabling transparent hugepage by default like kernel 2.6.32 ? Hi, In my benchmarks, THP increase the memory transaction speed by 5-10% in the KVM guest if THP is activated on the host side, not in the VM side. I know that THP for databases is bad, but we are not using THP in the guest where the database lives. Can someone provide some benchmarks for that case or further information? Any suggestions? On Wed, Sep 9, 2015 at 3:45 PM, Daniel Hunsaker < danhunsa...@gmail.com > wrote: What about setting CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS = N? As I understand it, "not set" means "use the default setting the kernel devs think is the most sane for normal use", which in this case would be Y... On Wed, Sep 9, 2015, 06:58 Alexandre DERUMIER < aderum...@odiso.com > wrote: BQ_BEGIN >>I could set it in kernel config, for example: >> >>CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y >> >>would that help? Well, this is like "echo madvise > /sys/kernel/mm/transparent_hugepage/enabled" But I don't see how to set never. maybe # CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS is not set # CONFIG_TRANSPARENT_HUGEPAGE_MADVISE is not set But I don't known how to unset CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS in the new pve-kernel package makefile ? I have tried to add PVE_CONFIG_OPTS= \ .. -d CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS \ .. but it don't seem to work, I still have CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=Y in .config Any idea ? ----- Mail original ----- De: "dietmar" < diet...@proxmox.com > À: "aderumier" < aderum...@odiso.com >, "pve-devel" < pve-devel@pve.proxmox.com > Envoyé: Mercredi 9 Septembre 2015 06:33:05 Objet: Re: [pve-devel] disabling transparent hugepage by default like kernel 2.6.32 ? > I think it's better to disable it by default. > > echo never > /sys/kernel/mm/transparent_hugepage/enabled. > > (I don't known what is the best way to disable it by default) I could set it in kernel config, for example: CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y would that help? _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel BQ_END _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
