afe30b59d3
Avoid instructions with explicit uses of the stack pointer between instructions that implicitly refer to it. The sequence of POP %reg; ADD $x, %RSP; POP %reg forces emission of synchronization uop to synchronize the value of the stack pointer in the stack engine and the out-of-order core. Using POP with the dummy register instead of ADD $x, %RSP results in a smaller code size and faster code. The patch also fixes the reference to the wrong register in the nearby comment. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20220816211010.25693-1-ubizjak@gmail.com Signed-off-by: Sean Christopherson <seanjc@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.