On Tue, Jul 03, 2012 at 07:16:04AM -0500, W. Michael Petullo wrote: > >> We have seen a significant reduction in performance in our research DomU > >> OS kernel when running on Fedora 16 with Linux 3.4.2 vs. 3.3.7. We run > > a series of benchmarks which are DomU-kernel-space-CPU-heavy; many of > >> these run 10x slower when using the 3.4.2 Linux kernel as Dom0. > >> > >> This is a little surprising---we've been tracking the Fedora kernels for > >> a long time with no problem like this. Did anyone else notice any changes? > >> > > > > Just to verify.. both the 3.3.7 and 3.4.2 Linux kernel are 'release' builds? > > and not debug-versions from rawhide? > > Yes, they are the Fedora 16 release builds. The commits that went in (3.4) were: 1fd1443 xen/Kconfig: fix Kconfig layout 76a8df7 xen/pci: don't use PCI BIOS service for configuration space accesses b7e5ffe xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEs 558daa2 xen/apic: Return the APIC ID (and version) for CPU 0. a7a97c6 drivers/video/xen-fbfront.c: add missing cleanup code 7eb7ce4 xen: correctly check for pending events when restoring irq flags b930fe5 xen/acpi: Workaround broken BIOSes exporting non-existing C-states. cf405ae xen/smp: Fix crash when booting with ACPI hotplug CPUs. 521394e xen: use the pirq number to check the pirq_eoi_map df88b2d xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded. cd74257 x86, acpi: Call acpi_enter_sleep_state via an asmlinkage C function from assembler 2a14e54 ACPI: Convert wake_sleep_flags to a value instead of function 3d81acb Revert "xen/p2m: m2p_find_override: use list_for_each_entry_safe" 186bab1 xen/resume: Fix compile warnings. 3066616 xen/xenbus: Add quirk to deal with misconfigured backends. a71e23d xen/blkback: Fix warning error. b960d6c xen/p2m: m2p_find_override: use list_for_each_entry_safe e8e937b xen/gntdev: do not set VM_PFNMAP 6b5e7d9 xen/grant-table: add error-handling code on failure of gnttab_resume f09d843 xen/pcifront: avoid pci_frontend_enable_msix() falsely returning success 0ee46ec xen/pciback: fix XEN_PCI_OP_enable_msix result e8c9e78 xen/smp: Remove unnecessary call to smp_processor_id() 2531d64 xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries' e95ae5a xen: only check xen_platform_pci_unplug if hvm 136d249 x86/ioapic: Add io_apic_ops driver layer to allow interception 3389bb8 xen/blkback: Make optional features be really optional. 4dae767 xen/blkback: Squash the discard support for 'file' and 'phy' type. df7a3ee xen/acpi: Fix Kconfig dependency on CPU_FREQ f132c5b Fix full_name_hash() behaviour when length is a multiple of 8 b9136d2 xen: initialize platform-pci even if xen_emul_unplug=never 106b443 xen/smp: Fix bringup bug in AP code. 27257fc xen/acpi: Remove the WARN's as they just create noise. 8e6f7c2 xen/tmem: cleanup 9846ff1 xen: support pirq_eoi_map 102b208 xen/acpi-processor: Do not depend on CPU frequency scaling drivers. 48cdd82 xen/cpufreq: Disable the cpu frequency scaling drivers from loading. 448c8b1 provide disable_cpufreq() function to disable the API. 3467811 xen-blkfront: make blkif_io_lock spinlock per-device dad5cf6 xen/blkfront: don't put bdev right after getting it 34ae2e4 xen-blkfront: use bitmap_set() and bitmap_clear() b2167ba xen/blkback: Enable blkback on HVM guests 4f14faa xen/blkback: use grant-table.c hypercall wrappers 4bc25af xen kconfig: relax INPUT_XEN_KBDDEV_FRONTEND deps a7b422c provide disable_cpufreq() function to disable the API. 59a5680 xen/acpi-processor: C and P-state driver that uploads said data to hypervisor. ead1d01 xen: constify all instances of "struct attribute_group" 42c46e6 xen/xenbus: ignore console/0 cf8e019 hvc_xen: introduce HVC_XEN_FRONTEND 02e19f9 hvc_xen: implement multiconsole support eb5ef07 hvc_xen: support PV on HVM consoles bd0d5aa xenbus: don't free other end details too early a1f37788 tboot: Add return values for tboot_sleep 09f98a8 x86, acpi, tboot: Have a ACPI os prepare sleep instead of calling tboot_sleep. 73c154c xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it. cc7335b xen/setup/pm/acpi: Remove the call to boot_option_idle_override. 5ac0800 xenbus: address compiler warnings 1160831 xen/pciback: Support pci_reset_function, aka FLR or D3 support. 6fbf9e7 PCI: Introduce __pci_reset_function_locked to be used when holding device_lock. cf66f9d xen/netfront: add netconsole support. f3ff924 Remove useless get_driver()/put_driver() calls 2113f46 xen: use this_cpu_xxx replace percpu_xxx funcs cd9db80 xen/pciback: Support pci_reset_function, aka FLR or D3 support. a96d627 pci: Introduce __pci_reset_function_locked to be used when holding device_lock. 8605c68 xen: Utilize the restore_msi_irqs hook. So one thing that you might be hitting is that now the CPU freq driver is uploading the data to the hypervisor - the hypervisor might be doing power-save stuff instead of concentrating on giving your raw performance. So can you start with 'cpufreq=verbose,performance' on your hypervisor line. Besides that..there is: 9846ff1 xen: support pirq_eoi_map (and its fix) 521394e xen: use the pirq number to check the pirq_eoi_map See if reverting those makes issues go away. > > -- > Mike > > :wq > -- > xen mailing list > xen@xxxxxxxxxxxxxxxxxxxxxxx > https://admin.fedoraproject.org/mailman/listinfo/xen -- xen mailing list xen@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/xen
