bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-04-24 14:07:52 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

static_call: Add inline static call infrastructure

Browse source 
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
This commit is contained in:
Josh Poimboeuf 2020-08-18 15:57:42 +02:00 • committed by Ingo Molnar
parent 115284d89a
commit 9183c3f9ed
8 changed files with 373 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

5
include/linux/module.h
View file

@ -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? */