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Nicholas Piggin
77f68ebeee
On a 16-socket 192-core POWER8 system, the context_switch1_threads benchmark from will-it-scale (see earlier changelog), upstream can achieve a rate of about 1 million context switches per second, due to contention on the mm refcount. 64s meets the prerequisites for CONFIG_MMU_LAZY_TLB_SHOOTDOWN, so enable the option. This increases the above benchmark to 118 million context switches per second. This generates 314 additional IPI interrupts on a 144 CPU system doing a kernel compile, which is in the noise in terms of kernel cycles. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Nicholas Piggin <[email protected]> Acked-by: Linus Torvalds <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Christophe Leroy <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
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.