10 Mar, 2010
1 commit
-
Events that trigger overflows by interrupting a context can
use get_irq_regs() or task_pt_regs() to retrieve the state
when the event triggered. But this is not the case for some
other class of events like trace events as tracepoints are
executed in the same context than the code that triggered
the event.It means we need a different api to capture the regs there,
namely we need a hot snapshot to get the most important
informations for perf: the instruction pointer to get the
event origin, the frame pointer for the callchain, the code
segment for user_mode() tests (we always use __KERNEL_CS as
trace events always occur from the kernel) and the eflags
for further purposes.v2: rename perf_save_regs to perf_fetch_caller_regs as per
Masami's suggestion.Signed-off-by: Frederic Weisbecker
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: H. Peter Anvin
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Steven Rostedt
Cc: Arnaldo Carvalho de Melo
Cc: Masami Hiramatsu
Cc: Jason Baron
Cc: Archs
17 Dec, 2009
1 commit
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The current print_context_stack helper that does the stack
walking job is good for usual stacktraces as it walks through
all the stack and reports even addresses that look unreliable,
which is nice when we don't have frame pointers for example.But we have users like perf that only require reliable
stacktraces, and those may want a more adapted stack walker, so
lets make this function a callback in stacktrace_ops that users
can tune for their needs.Signed-off-by: Frederic Weisbecker
Cc: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar
14 Apr, 2009
1 commit
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Impact: cleanup
asm/stacktrace.h is more appropriate so removing other 2 declarations.
Signed-off-by: Jaswinder Singh Rajput
Cc: Neil Horman
LKML-Reference:
Signed-off-by: Ingo Molnar
03 Dec, 2008
1 commit
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Impact: better dumpstack output
I noticed in my crash dumps and even in the stack tracer that a
lot of functions listed in the stack trace are simply
return_to_handler which is ftrace graphs way to insert its own
call into the return of a function.But we lose out where the actually function was called from.
This patch adds in hooks to the dumpstack mechanism that detects
this and finds the real function to print. Both are printed to
let the user know that a hook is still in place.This does give a funny side effect in the stack tracer output:
Depth Size Location (80 entries)
----- ---- --------
0) 4144 48 save_stack_trace+0x2f/0x4d
1) 4096 128 ftrace_call+0x5/0x2b
2) 3968 16 mempool_alloc_slab+0x16/0x18
3) 3952 384 return_to_handler+0x0/0x73
4) 3568 -240 stack_trace_call+0x11d/0x209
5) 3808 144 return_to_handler+0x0/0x73
6) 3664 -128 mempool_alloc+0x4d/0xfe
7) 3792 128 return_to_handler+0x0/0x73
8) 3664 -32 scsi_sg_alloc+0x48/0x4a [scsi_mod]As you can see, the real functions are now negative. This is due
to them not being found inside the stack.Signed-off-by: Steven Rostedt
Signed-off-by: Ingo Molnar
28 Oct, 2008
1 commit
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Impact: cleanup
As promised, now that dumpstack_32 and dumpstack_64 have so many bits
in common, we should merge the in-sync bits into a common file, to
prevent them from diverging again.This patch removes bits which are common between dumpstack_32.c and
dumpstack_64.c and places them in a common dumpstack.c which is built
for both 32 and 64 bit arches.Signed-off-by: Neil Horman
Acked-by: Alexander van Heukelum
Signed-off-by: Ingo MolnarMakefile | 2
arch/x86/kernel/Makefile | 2
arch/x86/kernel/Makefile | 2
arch/x86/kernel/Makefile | 2
arch/x86/kernel/Makefile | 2
arch/x86/kernel/Makefile | 2
arch/x86/kernel/dumpstack.c | 319 +++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/dumpstack.h | 39 +++++
arch/x86/kernel/dumpstack_32.c | 294 -------------------------------------
arch/x86/kernel/dumpstack_64.c | 285 ------------------------------------
5 files changed, 363 insertions(+), 576 deletions(-)
