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| author | Ingo Molnar <mingo@elte.hu> | 2008-07-17 17:40:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-17 17:40:48 +0200 |
| commit | 2464a609ded094204a3aed24823745ec58e3c879 (patch) | |
| tree | 54080daf81746787dbd11160752e04b9652b8728 | |
| parent | c349e0a01c3e0f70913db6a5bb61ab204e0602de (diff) | |
| download | linux-3.10-2464a609ded094204a3aed24823745ec58e3c879.tar.gz linux-3.10-2464a609ded094204a3aed24823745ec58e3c879.tar.bz2 linux-3.10-2464a609ded094204a3aed24823745ec58e3c879.zip | |
ftrace: do not trace library functions
make function tracing more robust: do not trace library functions.
We've already got a sizable list of exceptions:
ifdef CONFIG_FTRACE
# Do not profile string.o, since it may be used in early boot or vdso
CFLAGS_REMOVE_string.o = -pg
# Also do not profile any debug utilities
CFLAGS_REMOVE_spinlock_debug.o = -pg
CFLAGS_REMOVE_list_debug.o = -pg
CFLAGS_REMOVE_debugobjects.o = -pg
CFLAGS_REMOVE_find_next_bit.o = -pg
CFLAGS_REMOVE_cpumask.o = -pg
CFLAGS_REMOVE_bitmap.o = -pg
endif
... and the pattern has been that random library functionality showed
up in ftrace's critical path (outside of its recursion check), causing
hard to debug lockups.
So be a bit defensive about it and exclude all lib/*.o functions by
default. It's not that they are overly interesting for tracing purposes
anyway. Specific ones can still be traced, in an opt-in manner.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | lib/Makefile | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/lib/Makefile b/lib/Makefile index d90d31102e0..818c4d45551 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -2,24 +2,17 @@ # Makefile for some libs needed in the kernel. # +ifdef CONFIG_FTRACE +ORIG_CFLAGS := $(KBUILD_CFLAGS) +KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) +endif + lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o prio_heap.o ratelimit.o -ifdef CONFIG_FTRACE -# Do not profile string.o, since it may be used in early boot or vdso -CFLAGS_REMOVE_string.o = -pg -# Also do not profile any debug utilities -CFLAGS_REMOVE_spinlock_debug.o = -pg -CFLAGS_REMOVE_list_debug.o = -pg -CFLAGS_REMOVE_debugobjects.o = -pg -CFLAGS_REMOVE_find_next_bit.o = -pg -CFLAGS_REMOVE_cpumask.o = -pg -CFLAGS_REMOVE_bitmap.o = -pg -endif - lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o |