Messages in this thread | | | Date | Fri, 10 Jul 2020 17:56:02 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v6 06/17] static_call: Add basic static call infrastructure |
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On Fri, 10 Jul 2020 15:38:37 +0200 Peter Zijlstra <peterz@infradead.org> wrote:
> From: Josh Poimboeuf <jpoimboe@redhat.com> > > Static calls are a replacement for global function pointers. They use > code patching to allow direct calls to be used instead of indirect > calls. They give the flexibility of function pointers, but with > improved performance. This is especially important for cases where > retpolines would otherwise be used, as retpolines can significantly > impact performance. > > The concept and code are an extension of previous work done by Ard > Biesheuvel and Steven Rostedt: > > https://lkml.kernel.org/r/20181005081333.15018-1-ard.biesheuvel@linaro.org > https://lkml.kernel.org/r/20181006015110.653946300@goodmis.org > > There are two implementations, depending on arch support: > > 1) out-of-line: patched trampolines (CONFIG_HAVE_STATIC_CALL) > 2) basic function pointers > > For more details, see the comments in include/linux/static_call.h. > > [peterz: simplified interface] > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
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