21 Apr
2017
21 Apr
'17
10:44 a.m.
--Apple-Mail=_1B8461A0-C40E-47B7-B0E6-39D36113183A Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On 20 Apr 2017, at 17:39, Gianluca Cecchi <gianluca.cecchi@gmail.com> = wrote: >=20 > On Thu, Apr 20, 2017 at 10:35 AM, Michal Skrivanek = <mskrivan@redhat.com <mailto:mskrivan@redhat.com>> wrote: >=20 >> On 19 Apr 2017, at 16:28, Gianluca Cecchi <gianluca.cecchi@gmail.com = <mailto:gianluca.cecchi@gmail.com>> wrote: >>=20 >> On Wed, Apr 19, 2017 at 3:44 PM, Martin Polednik = <mpolednik@redhat.com <mailto:mpolednik@redhat.com>> wrote: >>=20 >>=20 >> If you are using recent CentOS (or I guess Fedora), there isn't any >> extra setup required. Just create the custom property: >>=20 >> Both my engine and my hosts are CentOS 7.3 + updates >=20 > that=E2=80=99s good >=20 >> =20 >>=20 >> On the host where engine is running: >>=20 >> $ engine-config -s "UserDefinedVMProperties=3Dhugepages=3D^.*$" >> $ service ovirt-engine restart >>=20 >> and you should see 'hugepages' when editing a VM under custom = properties. >>=20 >> So no vdsm hook at all to install? >=20 > today you still need the hook. >=20 >>=20 >> =20 >> Set the number to (desired memory / 2048) and you're good to go. The >> VM will run with it's memory backed by hugepages. >>=20 >> As in sysctl.conf? So that if I want 4Gb of Huge Pages I have to set = 2048? >=20 > yes. there might be some=20 >=20 >>=20 >> =20 >> If you need >> hugepages even inside the VM, do whatever you would do on a physical >> host. >>=20 >> mpolednik >>=20 >>=20 >> yes, the main subject is to have Huge Pages inside the guest, so that = Oracle RDBMS at startup detect them and use them >=20 > yes, so if you do that via sysctl.conf on real HW just do the same = here, or modify kernel cmdline. >=20 > Note that those are two separate things > the hook is making QEMU process use hugepages memory in the host - = that improves performance of any VM > then how it looks in guest is no concern to oVirt, it=E2=80=99s = guest-side hugepages. You can enable/set them regardless the previous = step, which may be fine if you just want to expose the capability to = some app - e.g. in testing that the guest-side Oracle can work with = hugepages in the guest. > But you probably want both Oracle to see hugepages and also actually = use them - then you need both reserve that on host for qemu process and = then inside guest reserve that for oracle. I.e. you need to add a = =E2=80=9Cbuffer=E2=80=9D on host side to accommodate the non-hugepages = parts of the guest e.g. on 24GB host you can reserve 20GB hugepages for = VMs to use, and then run a VM with 20GB memory, reserving 16GB hugepages = inside the guest for oracle to use. >=20 > Thanks, > michal >=20 >>=20 >> Gianluca=20 >=20 >=20 > I'm making some tests right now.=20 > Steps done:=20 > - configure huge pages on hypervisor >=20 > [root@ractor ~]# cat /etc/sysctl.d/huge-pages.conf=20 > # 20/04/2017 8Gb > vm.nr_hugepages =3D 4096 > [root@ractor ~]#=20 >=20 > rebooted host (I also updated in the mean time it to latest 4.1.1 = packages with vdsm-4.19.10.1-1.el7.centos.x86_64 and = vdsm-hook-hugepages-4.19.10.1-1.el7.centos.noarch) > I also set "transparent_hugepage=3Dnever" boot parameter because I = know that they are in conflict with Huge Pages >=20 > So the situation is: >=20 > [root@ractor ~]# cat /proc/cmdline=20 > BOOT_IMAGE=3D/vmlinuz-3.10.0-514.16.1.el7.x86_64 = root=3D/dev/mapper/centos-root ro rd.lvm.lv = <http://rd.lvm.lv/>=3Dcentos/root rd.lvm.lv = <http://rd.lvm.lv/>=3Dcentos/swap rhgb quiet LANG=3Den_US.UTF-8 = transparent_hugepage=3Dnever > [root@ractor ~]#=20 >=20 > [root@ractor ~]# cat /proc/meminfo | grep -i huge > AnonHugePages: 0 kB > HugePages_Total: 4096 > HugePages_Free: 4096 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB > [root@ractor ~]#=20 >=20 > I edited a pre-existing CentOS 6 VM setting for it 8Gb of ram and 2048 = pages (4Gb) in custom property forhugepages. >=20 > When I power on I get this addition in qemu-kvm process definition as = expected: >=20 > -mem-path /dev/hugepages/libvirt/qemu >=20 > I noticed that now I have on host.... >=20 > [root@ractor vdsm]# cat /proc/meminfo | grep -i huge > AnonHugePages: 0 kB > HugePages_Total: 6144 > HugePages_Free: 2048 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB > [root@ractor vdsm]#=20 >=20 > So apparently it did allocated 2048 new huge pages... > Does it mean that actually I have not to pre-allocate huge pages at = all on host and it eventually will increase them (but not able to remove = then I suppose) ? >=20 > Anyway the count doesn't seem correct... because it seems that a total = of 4096 pages are in use/locked... (HugePages_Total - HugePages_Free + = HugePages_Rsvd) > while they should be 2048..... >=20 > [root@ractor vdsm]# ll /dev/hugepages/libvirt/qemu/ > total 0 > [root@ractor vdsm]# ll /hugetlbfs/libvirt/qemu/ > total 0 > [root@ractor vdsm]#=20 >=20 > If I power off the VM >=20 > [root@ractor vdsm]# cat /proc/meminfo | grep -i huge > AnonHugePages: 0 kB > HugePages_Total: 4096 > HugePages_Free: 4096 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB > [root@ractor vdsm]#=20 >=20 > Does this mean that in CentOS 7.3 Huge Pages could be reclaimed....??? it tries to=E2=80=A6well, as I said, the hook is being improved right = now and in 4.2 it will likely be more consumable >=20 > Nevertheless, when I configure huge pages in guest it seems to work as = expected >=20 > [root@dbtest ~]# cat /proc/meminfo | grep -i huge > AnonHugePages: 0 kB > HugePages_Total: 2048 > HugePages_Free: 2048 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB >=20 > Going into Oracle DB initialization, after configuring its dedicated = memory (SGA) to 2354Mb, I get this confirmation inside its log file Yes, but that would always work even without setting things up on host. = The =E2=80=9Conly=E2=80=9D difference would be the actual performance. >=20 > Thu Apr 20 17:16:27 2017 > Per process system memlock (soft) limit =3D 4096M > Thu Apr 20 17:16:27 2017 > Expected per process system memlock (soft) limit to lock > SHARED GLOBAL AREA (SGA) into memory: 2354M > Thu Apr 20 17:16:27 2017 > Available system pagesizes: > 4K, 2048K=20 > Thu Apr 20 17:16:27 2017 > Supported system pagesize(s): > Thu Apr 20 17:16:27 2017 > PAGESIZE AVAILABLE_PAGES EXPECTED_PAGES ALLOCATED_PAGES ERROR(s) > Thu Apr 20 17:16:27 2017 > 4K Configured 3 3 = NONE > Thu Apr 20 17:16:27 2017 > 2048K 2048 1177 1177 = NONE >=20 > Gianluca >=20 --Apple-Mail=_1B8461A0-C40E-47B7-B0E6-39D36113183A Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 <html><head><meta http-equiv=3D"Content-Type" content=3D"text/html = charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" = class=3D""><br class=3D""><div><blockquote type=3D"cite" class=3D""><div = class=3D"">On 20 Apr 2017, at 17:39, Gianluca Cecchi <<a = href=3D"mailto:gianluca.cecchi@gmail.com" = class=3D"">gianluca.cecchi@gmail.com</a>> wrote:</div><br = class=3D"Apple-interchange-newline"><div class=3D""><div dir=3D"ltr" = class=3D""><div class=3D"gmail_extra"><div class=3D"gmail_quote">On Thu, = Apr 20, 2017 at 10:35 AM, Michal Skrivanek <span dir=3D"ltr" = class=3D""><<a href=3D"mailto:mskrivan@redhat.com" target=3D"_blank" = class=3D"">mskrivan@redhat.com</a>></span> wrote:<br = class=3D""><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px = 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div = style=3D"word-wrap:break-word" class=3D""><br class=3D""><div = class=3D""><span class=3D"gmail-m_5930415786222383046gmail-"><blockquote = type=3D"cite" class=3D""><div class=3D"">On 19 Apr 2017, at 16:28, = Gianluca Cecchi <<a href=3D"mailto:gianluca.cecchi@gmail.com" = target=3D"_blank" class=3D"">gianluca.cecchi@gmail.com</a>> = wrote:</div><br = class=3D"gmail-m_5930415786222383046gmail-m_-6852186268654812432Apple-inte= rchange-newline"><div class=3D""><div dir=3D"ltr" class=3D""><div = class=3D"gmail_extra"><div class=3D"gmail_quote">On Wed, Apr 19, 2017 at = 3:44 PM, Martin Polednik <span dir=3D"ltr" class=3D""><<a = href=3D"mailto:mpolednik@redhat.com" target=3D"_blank" = class=3D"">mpolednik@redhat.com</a>></span> wrote:<br = class=3D""><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px = 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div = class=3D"gmail-m_5930415786222383046gmail-m_-6852186268654812432HOEnZb"><d= iv = class=3D"gmail-m_5930415786222383046gmail-m_-6852186268654812432h5"><block= quote class=3D"gmail_quote" style=3D"margin:0px 0px 0px = 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br = class=3D""> </blockquote> <br class=3D""></div></div> If you are using recent CentOS (or I guess Fedora), there isn't any<br = class=3D""> extra setup required. Just create the custom property:<br = class=3D""></blockquote><div class=3D""><br class=3D""></div><div = class=3D"">Both my engine and my hosts are CentOS 7.3 + = updates</div></div></div></div></div></blockquote><div class=3D""><br = class=3D""></div></span>that=E2=80=99s good</div><div class=3D""><span = class=3D"gmail-m_5930415786222383046gmail-"><br class=3D""><blockquote = type=3D"cite" class=3D""><div class=3D""><div dir=3D"ltr" class=3D""><div = class=3D"gmail_extra"><div class=3D"gmail_quote"><div = class=3D""> </div><blockquote class=3D"gmail_quote" = style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid = rgb(204,204,204);padding-left:1ex"> <br class=3D""> On the host where engine is running:<br class=3D""> <br class=3D""> $ engine-config -s "UserDefinedVMProperties=3Dhugep<wbr = class=3D"">ages=3D^.*$"<br class=3D""> $ service ovirt-engine restart<br class=3D""> <br class=3D""> and you should see 'hugepages' when editing a VM under custom = properties.<br class=3D""></blockquote><div class=3D""><br = class=3D""></div><div class=3D"">So no vdsm hook at all to = install?</div></div></div></div></div></blockquote><div class=3D""><br = class=3D""></div></span>today you still need the hook.</div><div = class=3D""><span class=3D"gmail-m_5930415786222383046gmail-"><br = class=3D""><blockquote type=3D"cite" class=3D""><div class=3D""><div = dir=3D"ltr" class=3D""><div class=3D"gmail_extra"><div = class=3D"gmail_quote"><div class=3D""><br class=3D""></div><div = class=3D""> </div><blockquote class=3D"gmail_quote" = style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid = rgb(204,204,204);padding-left:1ex"> Set the number to (desired memory / 2048) and you're good to go. The<br = class=3D""> VM will run with it's memory backed by hugepages. </blockquote><div = class=3D""><br class=3D""></div><div class=3D"">As in sysctl.conf? So = that if I want 4Gb of Huge Pages I have to set = 2048?</div></div></div></div></div></blockquote><div class=3D""><br = class=3D""></div></span>yes. there might be some </div><div = class=3D""><span class=3D"gmail-m_5930415786222383046gmail-"><br = class=3D""><blockquote type=3D"cite" class=3D""><div class=3D""><div = dir=3D"ltr" class=3D""><div class=3D"gmail_extra"><div = class=3D"gmail_quote"><div class=3D""><br class=3D""></div><div = class=3D""> </div><blockquote class=3D"gmail_quote" = style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid = rgb(204,204,204);padding-left:1ex">If you need<br class=3D""> hugepages even inside the VM, do whatever you would do on a physical<br = class=3D""> host.<br class=3D""> <br class=3D""> mpolednik<div = class=3D"gmail-m_5930415786222383046gmail-m_-6852186268654812432HOEnZb"><d= iv class=3D"gmail-m_5930415786222383046gmail-m_-6852186268654812432h5"><br= class=3D""></div></div></blockquote><div class=3D""><br = class=3D""></div><div class=3D"">yes, the main subject is to have Huge = Pages inside the guest, so that Oracle RDBMS at startup detect them and = use them</div></div></div></div></div></blockquote><div class=3D""><br = class=3D""></div></span>yes, so if you do that via sysctl.conf on real = HW just do the same here, or modify kernel cmdline.</div><div = class=3D""><br class=3D""></div><div class=3D"">Note that those are two = separate things</div><div class=3D"">the hook is making QEMU process use = hugepages memory in the host - that improves performance of any = VM</div><div class=3D"">then how it looks in guest is no concern to = oVirt, it=E2=80=99s guest-side hugepages. You can enable/set them = regardless the previous step, which may be fine if you just want to = expose the capability to some app - e.g. in testing that the = guest-side Oracle can work with hugepages in the guest.</div><div = class=3D"">But you probably want both Oracle to see hugepages and also = actually use them - then you need both reserve that on host for qemu = process and then inside guest reserve that for oracle. I.e. you need to = add a =E2=80=9Cbuffer=E2=80=9D on host side to accommodate the = non-hugepages parts of the guest e.g. on 24GB host you can reserve 20GB = hugepages for VMs to use, and then run a VM with 20GB memory, reserving = 16GB hugepages inside the guest for oracle to use.</div><div = class=3D""><br class=3D""></div><div class=3D"">Thanks,</div><div = class=3D"">michal</div><div class=3D""><br class=3D""><blockquote = type=3D"cite" class=3D""><div class=3D""><div dir=3D"ltr" class=3D""><div = class=3D"gmail_extra"><div class=3D"gmail_quote"><div class=3D""><br = class=3D""></div><div class=3D"">Gianluca </div></div></div></div> </div></blockquote></div><br class=3D""></div></blockquote><div = class=3D""><br class=3D""></div><div class=3D"">I'm making some tests = right now. </div><div class=3D"">Steps done: </div><div = class=3D"">- configure huge pages on hypervisor</div><div class=3D""><br = class=3D""></div><div class=3D""><div class=3D"">[root@ractor ~]# cat = /etc/sysctl.d/huge-pages.conf </div><div class=3D""># 20/04/2017 = 8Gb</div><div class=3D"">vm.nr_hugepages =3D 4096</div><div = class=3D"">[root@ractor ~]# </div></div><div class=3D""><br = class=3D""></div><div class=3D"">rebooted host (I also updated in the = mean time it to latest 4.1.1 packages = with vdsm-4.19.10.1-1.el7.<wbr class=3D"">centos.x86_64 = and vdsm-hook-hugepages-4.19.<wbr = class=3D"">10.1-1.el7.centos.noarch)</div><div class=3D"">I also set = "transparent_hugepage=3Dnever" boot parameter because I know that they = are in conflict with Huge Pages</div><div class=3D""><br = class=3D""></div><div class=3D"">So the situation is:</div><div = class=3D""><br class=3D""></div><div class=3D""><div = class=3D"">[root@ractor ~]# cat /proc/cmdline </div><div = class=3D"">BOOT_IMAGE=3D/vmlinuz-3.10.0-<wbr = class=3D"">514.16.1.el7.x86_64 root=3D/dev/mapper/centos-root ro <a = href=3D"http://rd.lvm.lv/" target=3D"_blank" = class=3D"">rd.lvm.lv</a>=3Dcentos/root <a href=3D"http://rd.lvm.lv/" = target=3D"_blank" class=3D"">rd.lvm.lv</a>=3Dcentos/swap rhgb quiet = LANG=3Den_US.UTF-8 transparent_hugepage=3Dnever</div><div = class=3D"">[root@ractor ~]# </div></div><div class=3D""><br = class=3D""></div><div class=3D""><div class=3D"">[root@ractor ~]# cat = /proc/meminfo | grep -i huge</div><div class=3D"">AnonHugePages: = 0 kB</div><div class=3D"">HugePages_Total: = 4096</div><div class=3D"">HugePages_Free: = 4096</div><div class=3D"">HugePages_Rsvd: = 0</div><div class=3D"">HugePages_Surp: = 0</div><div class=3D"">Hugepagesize: 2048 = kB</div><div class=3D"">[root@ractor ~]# </div></div><div = class=3D""><br class=3D""></div><div class=3D"">I edited a pre-existing = CentOS 6 VM setting for it 8Gb of ram and 2048 pages (4Gb) in custom = property forhugepages.</div><div class=3D""><br class=3D""></div><div = class=3D"">When I power on I get this addition in qemu-kvm process = definition as expected:</div><div class=3D""><br class=3D""></div><div = class=3D"">-mem-path /dev/hugepages/libvirt/qemu<br class=3D""></div><div = class=3D""><br class=3D""></div><div class=3D"">I noticed that now I = have on host....</div><div class=3D""><br class=3D""></div><div = class=3D""><div class=3D"">[root@ractor vdsm]# cat /proc/meminfo | grep = -i huge</div><div class=3D"">AnonHugePages: = 0 kB</div><div class=3D"">HugePages_Total: 6144</div><div = class=3D"">HugePages_Free: 2048</div><div = class=3D"">HugePages_Rsvd: 0</div><div = class=3D"">HugePages_Surp: 0</div><div = class=3D"">Hugepagesize: 2048 kB</div><div = class=3D"">[root@ractor vdsm]# </div></div><div class=3D""><br = class=3D""></div><div class=3D"">So apparently it did allocated 2048 new = huge pages...</div></div></div><div class=3D"gmail_extra"><div = class=3D"">Does it mean that actually I have not to pre-allocate huge = pages at all on host and it eventually will increase them (but not able = to remove then I suppose) ?</div><div class=3D""><br class=3D""></div><div= class=3D"">Anyway the count doesn't seem correct... because it seems = that a total of 4096 pages are in use/locked... (HugePages_Total - = HugePages_Free + HugePages_Rsvd)</div><div class=3D"">while they = should be 2048.....</div><div class=3D""><br class=3D""></div><div = class=3D""><div class=3D"">[root@ractor vdsm]# ll = /dev/hugepages/libvirt/qemu/</div><div class=3D"">total 0</div><div = class=3D"">[root@ractor vdsm]# ll /hugetlbfs/libvirt/qemu/</div><div = class=3D"">total 0</div><div class=3D"">[root@ractor = vdsm]# </div></div><div class=3D""><br class=3D""></div><div = class=3D"">If I power off the VM</div><div class=3D""><br = class=3D""></div><div class=3D""><div class=3D"">[root@ractor vdsm]# cat = /proc/meminfo | grep -i huge</div><div class=3D"">AnonHugePages: = 0 kB</div><div class=3D"">HugePages_Total: = 4096</div><div class=3D"">HugePages_Free: = 4096</div><div class=3D"">HugePages_Rsvd: = 0</div><div class=3D"">HugePages_Surp: = 0</div><div class=3D"">Hugepagesize: 2048 = kB</div><div class=3D"">[root@ractor vdsm]# </div></div><div = class=3D""><br class=3D""></div><div class=3D"">Does this mean that in = CentOS 7.3 Huge Pages could be = reclaimed....???</div></div></div></div></blockquote><div><br = class=3D""></div>it tries to=E2=80=A6well, as I said, the hook is being = improved right now and in 4.2 it will likely be more = consumable</div><div><br class=3D""><blockquote type=3D"cite" = class=3D""><div class=3D""><div dir=3D"ltr" class=3D""><div = class=3D"gmail_extra"><div class=3D""><br class=3D""></div><div = class=3D"">Nevertheless, when I configure huge pages in guest it seems = to work as expected</div><div class=3D""><br class=3D""></div><div = class=3D""><div class=3D"">[root@dbtest ~]# cat /proc/meminfo | grep -i = huge</div><div class=3D"">AnonHugePages: 0 = kB</div><div class=3D"">HugePages_Total: 2048</div><div = class=3D"">HugePages_Free: 2048</div><div = class=3D"">HugePages_Rsvd: 0</div><div = class=3D"">HugePages_Surp: 0</div><div = class=3D"">Hugepagesize: 2048 kB</div><div = class=3D""><br class=3D""></div></div><div class=3D"">Going into Oracle = DB initialization, after configuring its dedicated memory (SGA) to = 2354Mb, I get this confirmation inside its log = file</div></div></div></div></blockquote><div><br class=3D""></div>Yes, = but that would always work even without setting things up on host. The = =E2=80=9Conly=E2=80=9D difference would be the actual = performance.</div><div><br class=3D""><blockquote type=3D"cite" = class=3D""><div class=3D""><div dir=3D"ltr" class=3D""><div = class=3D"gmail_extra"><div class=3D""><br class=3D""></div><div = class=3D""><div class=3D"">Thu Apr 20 17:16:27 2017</div><div = class=3D""> Per process system memlock (soft) limit =3D = 4096M</div><div class=3D"">Thu Apr 20 17:16:27 2017</div><div = class=3D""> Expected per process system memlock (soft) limit to = lock</div><div class=3D""> SHARED GLOBAL AREA (SGA) into memory: = 2354M</div><div class=3D"">Thu Apr 20 17:16:27 2017</div><div = class=3D""> Available system pagesizes:</div><div class=3D""> = 4K, 2048K </div><div class=3D"">Thu Apr 20 17:16:27 2017</div><div = class=3D""> Supported system pagesize(s):</div><div class=3D"">Thu = Apr 20 17:16:27 2017</div><div class=3D""> <b = class=3D"">PAGESIZE</b> AVAILABLE_PAGES EXPECTED_PAGES = <b class=3D"">ALLOCATED_PAGES</b> ERROR(s)</div><div = class=3D"">Thu Apr 20 17:16:27 2017</div><div class=3D""> = 4K Configured = 3 = 3 NONE</div><div class=3D"">Thu Apr 20 = 17:16:27 2017</div><div class=3D""> <b class=3D"">2048K= </b> 2048 = 1177 <b = class=3D"">1177</b> NONE</div></div><div = class=3D""><br class=3D""></div><div class=3D"">Gianluca</div><div = class=3D""><br class=3D""></div></div></div> </div></blockquote></div><br class=3D""></body></html>= --Apple-Mail=_1B8461A0-C40E-47B7-B0E6-39D36113183A--