From 9183c3f9ed710a8edf1a61e8a96d497258d26e08 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Tue, 18 Aug 2020 15:57:42 +0200
Subject: static_call: Add inline static call infrastructure
Add infrastructure for an arch-specific CONFIG_HAVE_STATIC_CALL_INLINE
option, which is a faster version of CONFIG_HAVE_STATIC_CALL. At
runtime, the static call sites are patched directly, rather than using
the out-of-line trampolines.
Compared to out-of-line static calls, the performance benefits are more
modest, but still measurable. Steven Rostedt did some tracepoint
measurements:
https://lkml.kernel.org/r/20181126155405.72b4f718@gandalf.local.home
This code is heavily inspired by the jump label code (aka "static
jumps"), as some of the concepts are very similar.
For more details, see the comments in include/linux/static_call.h.
[peterz: simplified interface; merged trampolines]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.684334440@infradead.org
---
include/linux/module.h | 5 +++++
1 file changed, 5 insertions(+)
(limited to 'include/linux/module.h')
diff --git a/include/linux/module.h b/include/linux/module.h
index e30ed5fa33a7..a29187f7c360 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -25,6 +25,7 @@
#include <linux/error-injection.h>
#include <linux/tracepoint-defs.h>
#include <linux/srcu.h>
+#include <linux/static_call_types.h>
#include <linux/percpu.h>
#include <asm/module.h>
@@ -498,6 +499,10 @@ struct module {
unsigned long *kprobe_blacklist;
unsigned int num_kprobe_blacklist;
#endif
+#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
+ int num_static_call_sites;
+ struct static_call_site *static_call_sites;
+#endif
#ifdef CONFIG_LIVEPATCH
bool klp; /* Is this a livepatch module? */
--
cgit v1.2.3-70-g09d2