Messages in this thread | | | Date | Mon, 08 Jun 2015 06:09:08 +0200 | From | Juergen Gross <> | Subject | Re: [PATCH 0/6] x86: reduce paravirtualized spinlock overhead |
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Ping?
Anything missing from my side?
On 04/30/2015 12:53 PM, Juergen Gross wrote: > Paravirtualized spinlocks produce some overhead even if the kernel is > running on bare metal. The main reason are the more complex locking > and unlocking functions. Especially unlocking is no longer just one > instruction but so complex that it is no longer inlined. > > This patch series addresses this issue by adding two more pvops > functions to reduce the size of the inlined spinlock functions. When > running on bare metal unlocking is again basically one instruction. > > Compile tested with CONFIG_PARAVIRT_SPINLOCKS on and off, 32 and 64 > bits. > > Functional testing on bare metal and as Xen dom0. > > Correct patching verified by disassembly of active kernel. > > Juergen Gross (6): > x86: use macro instead of "0" for setting TICKET_SLOWPATH_FLAG > x86: move decision about clearing slowpath flag into arch_spin_lock() > x86: introduce new pvops function clear_slowpath > x86: introduce new pvops function spin_unlock > x86: switch config from UNINLINE_SPIN_UNLOCK to INLINE_SPIN_UNLOCK > x86: remove no longer needed paravirt_ticketlocks_enabled > > arch/x86/Kconfig | 1 - > arch/x86/include/asm/paravirt.h | 13 +++++++++ > arch/x86/include/asm/paravirt_types.h | 12 ++++++++ > arch/x86/include/asm/spinlock.h | 53 ++++++++++++----------------------- > arch/x86/include/asm/spinlock_types.h | 3 +- > arch/x86/kernel/kvm.c | 14 +-------- > arch/x86/kernel/paravirt-spinlocks.c | 42 +++++++++++++++++++++++++-- > arch/x86/kernel/paravirt.c | 12 ++++++++ > arch/x86/kernel/paravirt_patch_32.c | 25 +++++++++++++++++ > arch/x86/kernel/paravirt_patch_64.c | 24 ++++++++++++++++ > arch/x86/xen/spinlock.c | 23 +-------------- > include/linux/spinlock_api_smp.h | 2 +- > kernel/Kconfig.locks | 7 +++-- > kernel/Kconfig.preempt | 3 +- > kernel/locking/spinlock.c | 2 +- > lib/Kconfig.debug | 1 - > 16 files changed, 154 insertions(+), 83 deletions(-)
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