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Wanpeng Li
4abaffce4d
In the vCPU reset and set APIC_BASE MSR path, the apic map will be recalculated several times, each time it will consume 10+ us observed by ftrace in my non-overcommit environment since the expensive memory allocate/mutex/rcu etc operations. This patch optimizes it by recaluating apic map in batch, I hope this can benefit the serverless scenario which can frequently create/destroy VMs. Before patch: kvm_lapic_reset ~27us After patch: kvm_lapic_reset ~14us Observed by ftrace, improve ~48%. Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.