Yes, the 4G/4G patch and the 64G options are both enabled for the hugemem kernel:
CONFIG_HIGHMEM64G=y CONFIG_X86_4G=y Differences between the "standard" kernel and the hugemem kernel: # diff config-2.4.21-47.ELsmp config-2.4.21-47.ELhugemem 2157,2158c2157,2158 < CONFIG_M686=y < # CONFIG_MPENTIUMIII is not set --- > # CONFIG_M686 is not set > CONFIG_MPENTIUMIII=y 2169c2169 < CONFIG_X86_PGE=y --- > # CONFIG_X86_PGE is not set 2193c2193 < # CONFIG_X86_4G is not set --- > CONFIG_X86_4G=y 2365,2366c2365 < CONFIG_M686=y < CONFIG_X86_PGE=y --- > CONFIG_MPENTIUMIII=y 2369,2372d2367 < # CONFIG_MXT is not set < CONFIG_HOTPLUG_PCI=y < CONFIG_HOTPLUG_PCI_COMPAQ=m < CONFIG_HOTPLUG_PCI_IBM=m 2373a2369 > CONFIG_X86_4G=y 2377,2379d2372 < # CONFIG_EWRK3 is not set < CONFIG_UNIX98_PTY_COUNT=2048 < CONFIG_HZ=512 2382a2376,2383 > # CONFIG_MXT is not set > CONFIG_HOTPLUG_PCI=y > CONFIG_HOTPLUG_PCI_COMPAQ=m > CONFIG_HOTPLUG_PCI_IBM=m > # CONFIG_EWRK3 is not set > CONFIG_UNIX98_PTY_COUNT=2048 > CONFIG_DEBUG_BUGVERBOSE=y > # CONFIG_PNPBIOS is not set Avi: Centos releases: http://isoredirect.centos.org/centos/3/isos/i386/ I am running RHEL3.8 which I do not see listed. Also, I'll need to work on a stock install and try to capture some kind of workload that exhibits the problem. It will be a couple of days. david Daniel P. Berrange wrote: > On Wed, Apr 30, 2008 at 07:39:53AM -0600, David S. Ahern wrote: >> Avi Kivity wrote: >>> David S. Ahern wrote: >>>> Another tidbit for you guys as I make my way through various >>>> permutations: >>>> I installed the RHEL3 hugemem kernel and the guest behavior is *much* >>>> better. >>>> System time still has some regular hiccups that are higher than xen >>>> and esx >>>> (e.g., 1 minute samples out of 5 show system time between 10 and 15%), >>>> but >>>> overall guest behavior is good with the hugemem kernel. >>>> >>>> >>> Wait, the amount of info here is overwhelming. Let's stick with the >>> current kernel (32-bit, HIGHMEM4G, right?) >>> >>> Did you get any traces with bypass_guest_pf=0? That may show more info. >>> >> My preference is to stick with the "standard", 32-bit RHEL3 kernel in the >> guest. >> My point in the last email was that the hugemem kernel shows a remarkable >> difference (it uses 3-levels of page tables right?). I was hoping that would >> ring a bell with someone. > > IIRC, the RHEL-3 hugemem kernel is using the 4g/4g split patches which > give userspace and kernelspace their own independant pagetables > > http://lwn.net/Articles/39925/ > http://lwn.net/Articles/39283/ > > Dan. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
