Messages in this thread | | | Date | Wed, 30 Jan 2013 22:57:01 +0100 | Subject | Re: [PATCH 8/8] cputime: Safely read cputime of full dynticks CPUs | From | Sedat Dilek <> |
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On Mon, Jan 28, 2013 at 10:51 PM, Sedat Dilek <sedat.dilek@gmail.com> wrote: > On Mon, Jan 28, 2013 at 8:04 PM, Frederic Weisbecker <fweisbec@gmail.com> wrote: >> While remotely reading the cputime of a task running in a >> full dynticks CPU, the values stored in utime/stime fields >> of struct task_struct may be stale. Its values may be those >> of the last kernel <-> user transition time snapshot and >> we need to add the tickless time spent since this snapshot. >> >> To fix this, flush the cputime of the dynticks CPUs on >> kernel <-> user transition and record the time / context >> where we did this. Then on top of this snapshot and the current >> time, perform the fixup on the reader side from task_times() >> accessors. >> >> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Ingo Molnar <mingo@kernel.org> >> Cc: Li Zhong <zhong@linux.vnet.ibm.com> >> Cc: Namhyung Kim <namhyung.kim@lge.com> >> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> >> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: Steven Rostedt <rostedt@goodmis.org> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> [fixed kvm module related build errors] >> Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> >> > > Can you explain a bit what is the difference between "3.8-rc4-nohz3" > and "full-dynticks-cputime-for-mingo" patchsets? > > Does the latter need no more EXPORT_SYMBOL_GPL for vtime_guest_enter() > and vtime_guest_exit() when CONFIG_KVM=m (see [1])? > > - Sedat - > > [1] https://lkml.org/lkml/2013/1/23/473
To answer my question by myself...
$ grep 'CONFIG_KVM=' linux/.config CONFIG_KVM=m
$ grep kvm deb-pkg.log CC arch/x86/kernel/kvm.o CC arch/x86/kernel/kvmclock.o LD arch/x86/kvm/built-in.o CC [M] arch/x86/kvm/vmx.o CC [M] arch/x86/kvm/../../../virt/kvm/kvm_main.o CC [M] arch/x86/kvm/../../../virt/kvm/ioapic.o CC [M] arch/x86/kvm/../../../virt/kvm/coalesced_mmio.o CC [M] arch/x86/kvm/../../../virt/kvm/irq_comm.o CC [M] arch/x86/kvm/../../../virt/kvm/eventfd.o CC [M] arch/x86/kvm/../../../virt/kvm/assigned-dev.o CC [M] arch/x86/kvm/../../../virt/kvm/iommu.o CC [M] arch/x86/kvm/../../../virt/kvm/async_pf.o CC [M] arch/x86/kvm/x86.o CC [M] arch/x86/kvm/mmu.o CC [M] arch/x86/kvm/emulate.o CC [M] arch/x86/kvm/i8259.o CC [M] arch/x86/kvm/irq.o CC [M] arch/x86/kvm/lapic.o CC [M] arch/x86/kvm/i8254.o CC [M] arch/x86/kvm/cpuid.o CC [M] arch/x86/kvm/pmu.o LD [M] arch/x86/kvm/kvm.o LD [M] arch/x86/kvm/kvm-intel.o CC arch/x86/kvm/kvm-intel.mod.o CC arch/x86/kvm/kvm.mod.o LD [M] arch/x86/kvm/kvm-intel.ko LD [M] arch/x86/kvm/kvm.ko INSTALL arch/x86/kvm/kvm-intel.ko INSTALL arch/x86/kvm/kvm.ko
...both EXPORT_SYMBOL_GPLs are no more needed!
- Sedat .
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