ae79270232
The kernel test robot measured a -1.6% performance regression on will-it-scale/sched_yield due to commit:2558aacff8("sched/hotplug: Ensure only per-cpu kthreads run during hotplug") Even though we were careful to replace a single load with another single load from the same cacheline. Restore finish_lock_switch() to the exact state before the offending patch and solve the problem differently. Fixes:2558aacff8("sched/hotplug: Ensure only per-cpu kthreads run during hotplug") Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20201210161408.GX3021@hirez.programming.kicks-ass.net
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.