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| author | Jason Baron <jbaron@redhat.com> | 2010-09-17 11:09:00 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-09-22 16:29:41 -0400 |
| commit | bf5438fca2950b03c21ad868090cc1a8fcd49536 (patch) | |
| tree | 9fc5693763263704de8d8ba1c37a84172dbe5eb7 /Makefile | |
| parent | fa6f2cc77081792e4edca9168420a3422299ef15 (diff) | |
| download | lwn-bf5438fca2950b03c21ad868090cc1a8fcd49536.tar.gz lwn-bf5438fca2950b03c21ad868090cc1a8fcd49536.zip | |
jump label: Base patch for jump label
base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>
[ cleaned up some formating ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 5 |
1 files changed, 5 insertions, 0 deletions
@@ -591,6 +591,11 @@ KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) # conserve stack if available KBUILD_CFLAGS += $(call cc-option,-fconserve-stack) +# check for 'asm goto' +ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y) + KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO +endif + # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments # But warn user when we do so warn-assign = \ |