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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/asm-generic/vmlinux.lds.h | |
| parent | 115284d89a436e9b66da0c6c4f6efded806874b2 (diff) | |
| download | linux-9183c3f9ed710a8edf1a61e8a96d497258d26e08.tar.gz | |
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/asm-generic/vmlinux.lds.h')
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 5430febd34bee..0088a5cd6a40c 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -388,6 +388,12 @@ KEEP(*(__jump_table)) \ __stop___jump_table = .; +#define STATIC_CALL_DATA \ + . = ALIGN(8); \ + __start_static_call_sites = .; \ + KEEP(*(.static_call_sites)) \ + __stop_static_call_sites = .; + /* * Allow architectures to handle ro_after_init data on their * own by defining an empty RO_AFTER_INIT_DATA. @@ -398,6 +404,7 @@ __start_ro_after_init = .; \ *(.data..ro_after_init) \ JUMP_TABLE_DATA \ + STATIC_CALL_DATA \ __end_ro_after_init = .; #endif |