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| author |   Josh Poimboeuf <jpoimboe@redhat.com> | 2020-08-18 15:57:42 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2020-09-01 09:58:04 +0200 |
| commit | 9183c3f9ed710a8edf1a61e8a96d497258d26e08 (patch) | |
| tree | b3434e44f45bb98d2decb831e77c3e2c48329663 /kernel/module.c | |
| parent | static_call: Add basic static call infrastructure (diff) | |
| download | linux-dev-9183c3f9ed710a8edf1a61e8a96d497258d26e08.tar.xz linux-dev-9183c3f9ed710a8edf1a61e8a96d497258d26e08.zip | |
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
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c index 3c465cf31d08..c075a18103fb 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3275,6 +3275,11 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(unsigned long), &mod->num_kprobe_blacklist); #endif +#ifdef CONFIG_HAVE_STATIC_CALL_INLINE + mod->static_call_sites = section_objs(info, ".static_call_sites", + sizeof(*mod->static_call_sites), + &mod->num_static_call_sites); +#endif mod->extable = section_objs(info, "__ex_table", sizeof(*mod->extable), &mod->num_exentries); |