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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 /include/linux/static_call_types.h | |
| parent | 115284d89a436e9b66da0c6c4f6efded806874b2 (diff) | |
| download | linux-9183c3f9ed710a8edf1a61e8a96d497258d26e08.tar.bz2 | |
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 'include/linux/static_call_types.h')
| -rw-r--r-- | include/linux/static_call_types.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/static_call_types.h b/include/linux/static_call_types.h index 5ed249dc47d3..408d345d83e1 100644 --- a/include/linux/static_call_types.h +++ b/include/linux/static_call_types.h @@ -2,14 +2,27 @@ #ifndef _STATIC_CALL_TYPES_H #define _STATIC_CALL_TYPES_H +#include <linux/types.h> #include <linux/stringify.h> #define STATIC_CALL_KEY_PREFIX __SCK__ +#define STATIC_CALL_KEY_PREFIX_STR __stringify(STATIC_CALL_KEY_PREFIX) +#define STATIC_CALL_KEY_PREFIX_LEN (sizeof(STATIC_CALL_KEY_PREFIX_STR) - 1) #define STATIC_CALL_KEY(name) __PASTE(STATIC_CALL_KEY_PREFIX, name) #define STATIC_CALL_TRAMP_PREFIX __SCT__ #define STATIC_CALL_TRAMP_PREFIX_STR __stringify(STATIC_CALL_TRAMP_PREFIX) +#define STATIC_CALL_TRAMP_PREFIX_LEN (sizeof(STATIC_CALL_TRAMP_PREFIX_STR) - 1) #define STATIC_CALL_TRAMP(name) __PASTE(STATIC_CALL_TRAMP_PREFIX, name) #define STATIC_CALL_TRAMP_STR(name) __stringify(STATIC_CALL_TRAMP(name)) +/* + * The static call site table needs to be created by external tooling (objtool + * or a compiler plugin). + */ +struct static_call_site { + s32 addr; + s32 key; +}; + #endif /* _STATIC_CALL_TYPES_H */ |