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601f8af01e
rmap_add() and rmap_recycle() both run in the context of the vCPU and thus we can use kvm_vcpu_gfn_to_memslot() to look up the memslot. This enables rmap_add() and rmap_recycle() to take advantage of vcpu->last_used_slot and avoid expensive memslot searching. This change improves the performance of "Populate memory time" in dirty_log_perf_test with tdp_mmu=N. In addition to improving the performance, "Populate memory time" no longer scales with the number of memslots in the VM. Command | Before | After ------------------------------- | ---------------- | ------------- ./dirty_log_perf_test -v64 -x1 | 15.18001570s | 14.99469366s ./dirty_log_perf_test -v64 -x64 | 18.71336392s | 14.98675076s Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210804222844.1419481-6-dmatlack@google.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.