mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-03-18 11:40:17 +01:00
fdccc3fb7a
Skip most of the PMU context switching overhead when ctx->nr_events is 0. 50% performance overhead was observed under an extreme testcase. Signed-off-by: leilei.lin <leilei.lin@alibaba-inc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: eranian@gmail.com Cc: jolsa@redhat.com Cc: linxiulei@gmail.com Cc: yang_oliver@hotmail.com Link: http://lkml.kernel.org/r/20170809002921.69813-1-leilei.lin@alibaba-inc.com [ Rewrote the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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.