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John Ogness
459fbe0069
Although wbinvd() is faster than flushing many individual pages, it blocks the memory bus for "long" periods of time (>100us), thus directly causing unusually large latencies on all CPUs, regardless of any CPU isolation features that may be active. This is an unpriviledged operatation as it is exposed to user space via the graphics subsystem. For 1024 pages, flushing those pages individually can take up to 2200us, but the task remains fully preemptible during that time. Signed-off-by: John Ogness <john.ogness@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: linux-rt-users <linux-rt-users@vger.kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.