Adding libdw DWARF post unwind support, which is part of elfutils-devel/libdw-dev package from version 0.158.
Also includes the test suite for dwarf unwinding, by adding the arch specific test code and the perf_regs_load function.
Jean Pihet (3): perf tests: Introduce perf_regs_load function on ARM perf tests: Add dwarf unwind test on ARM perf tools: Add libdw DWARF post unwind support for ARM
tools/perf/Makefile.perf | 2 +- tools/perf/arch/arm/Makefile | 7 ++++ tools/perf/arch/arm/include/perf_regs.h | 5 +++ tools/perf/arch/arm/tests/dwarf-unwind.c | 59 ++++++++++++++++++++++++++++++++ tools/perf/arch/arm/tests/regs_load.S | 51 +++++++++++++++++++++++++++ tools/perf/arch/arm/util/unwind-libdw.c | 36 +++++++++++++++++++ tools/perf/tests/builtin-test.c | 2 +- tools/perf/tests/tests.h | 2 +- 8 files changed, 161 insertions(+), 3 deletions(-) create mode 100644 tools/perf/arch/arm/tests/dwarf-unwind.c create mode 100644 tools/perf/arch/arm/tests/regs_load.S create mode 100644 tools/perf/arch/arm/util/unwind-libdw.c
---
- Rebased on latest acme/perf/core git tree, - Tested on quad-core ARMv7 machine
Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches.
It takes single argument as a pointer to the regs dump buffer and populates it with current registers values.
Signed-off-by: Jean Pihet jean.pihet@linaro.org Cc: Corey Ashford cjashfor@linux.vnet.ibm.com Cc: Frederic Weisbecker fweisbec@gmail.com Cc: Ingo Molnar mingo@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Arnaldo Carvalho de Melo acme@ghostprotocols.net Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@redhat.com --- tools/perf/arch/arm/Makefile | 1 + tools/perf/arch/arm/include/perf_regs.h | 2 ++ tools/perf/arch/arm/tests/regs_load.S | 51 +++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+) create mode 100644 tools/perf/arch/arm/tests/regs_load.S
diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 67e9b3d..9b8f87e 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -4,4 +4,5 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o endif diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h index 2a1cfde..1476ae7 100644 --- a/tools/perf/arch/arm/include/perf_regs.h +++ b/tools/perf/arch/arm/include/perf_regs.h @@ -5,6 +5,8 @@ #include "../../util/types.h" #include <asm/perf_regs.h>
+void perf_regs_load(u64 *regs); + #define PERF_REGS_MASK ((1ULL << PERF_REG_ARM_MAX) - 1) #define PERF_REG_IP PERF_REG_ARM_PC #define PERF_REG_SP PERF_REG_ARM_SP diff --git a/tools/perf/arch/arm/tests/regs_load.S b/tools/perf/arch/arm/tests/regs_load.S new file mode 100644 index 0000000..241c6df --- /dev/null +++ b/tools/perf/arch/arm/tests/regs_load.S @@ -0,0 +1,51 @@ +#include <linux/linkage.h> + +#define R0 0x00 +#define R1 0x08 +#define R2 0x10 +#define R3 0x18 +#define R4 0x20 +#define R5 0x28 +#define R6 0x30 +#define R7 0x38 +#define R8 0x40 +#define R9 0x48 +#define SL 0x50 +#define FP 0x58 +#define IP 0x60 +#define SP 0x68 +#define LR 0x70 +#define PC 0x78 + +@ Implementation of void perf_regs_load(u64 *regs); +@ +@ This functions fills in the 'regs' buffer from the actual registers values. +@ Note that the return values (i.e. caller values) of sp and lr +@ are retrieved and stored, in order to skip the call to this function. + +.text +.type perf_regs_load,%function +ENTRY(perf_regs_load) + push {r1} + + str r0, [r0, #R0] + str r1, [r0, #R1] + str r2, [r0, #R2] + str r3, [r0, #R3] + str r4, [r0, #R4] + str r5, [r0, #R5] + str r6, [r0, #R6] + str r7, [r0, #R7] + str r8, [r0, #R8] + str r9, [r0, #R9] + str sl, [r0, #SL] + str fp, [r0, #FP] + str ip, [r0, #IP] + add r1, sp, #4 @ Retrieve and save sp at entry time + str r1, [r0, #SP] + str lr, [r0, #LR] + str lr, [r0, #PC] @ Save caller PC + + pop {r1} + bx lr +ENDPROC(perf_regs_load)
A new version is coming asap after a review of the code with Steve.
Thx, Jean
On 3 March 2014 10:53, Jean Pihet jean.pihet@linaro.org wrote:
Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches.
It takes single argument as a pointer to the regs dump buffer and populates it with current registers values.
Signed-off-by: Jean Pihet jean.pihet@linaro.org Cc: Corey Ashford cjashfor@linux.vnet.ibm.com Cc: Frederic Weisbecker fweisbec@gmail.com Cc: Ingo Molnar mingo@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Arnaldo Carvalho de Melo acme@ghostprotocols.net Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@redhat.com
tools/perf/arch/arm/Makefile | 1 + tools/perf/arch/arm/include/perf_regs.h | 2 ++ tools/perf/arch/arm/tests/regs_load.S | 51 +++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+) create mode 100644 tools/perf/arch/arm/tests/regs_load.S
diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 67e9b3d..9b8f87e 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -4,4 +4,5 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o endif diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h index 2a1cfde..1476ae7 100644 --- a/tools/perf/arch/arm/include/perf_regs.h +++ b/tools/perf/arch/arm/include/perf_regs.h @@ -5,6 +5,8 @@ #include "../../util/types.h" #include <asm/perf_regs.h>
+void perf_regs_load(u64 *regs);
#define PERF_REGS_MASK ((1ULL << PERF_REG_ARM_MAX) - 1) #define PERF_REG_IP PERF_REG_ARM_PC #define PERF_REG_SP PERF_REG_ARM_SP diff --git a/tools/perf/arch/arm/tests/regs_load.S b/tools/perf/arch/arm/tests/regs_load.S new file mode 100644 index 0000000..241c6df --- /dev/null +++ b/tools/perf/arch/arm/tests/regs_load.S @@ -0,0 +1,51 @@ +#include <linux/linkage.h>
+#define R0 0x00 +#define R1 0x08 +#define R2 0x10 +#define R3 0x18 +#define R4 0x20 +#define R5 0x28 +#define R6 0x30 +#define R7 0x38 +#define R8 0x40 +#define R9 0x48 +#define SL 0x50 +#define FP 0x58 +#define IP 0x60 +#define SP 0x68 +#define LR 0x70 +#define PC 0x78
+@ Implementation of void perf_regs_load(u64 *regs); +@ +@ This functions fills in the 'regs' buffer from the actual registers values. +@ Note that the return values (i.e. caller values) of sp and lr +@ are retrieved and stored, in order to skip the call to this function.
+.text +.type perf_regs_load,%function +ENTRY(perf_regs_load)
push {r1}str r0, [r0, #R0]str r1, [r0, #R1]str r2, [r0, #R2]str r3, [r0, #R3]str r4, [r0, #R4]str r5, [r0, #R5]str r6, [r0, #R6]str r7, [r0, #R7]str r8, [r0, #R8]str r9, [r0, #R9]str sl, [r0, #SL]str fp, [r0, #FP]str ip, [r0, #IP]add r1, sp, #4 @ Retrieve and save sp at entry timestr r1, [r0, #SP]str lr, [r0, #LR]str lr, [r0, #PC] @ Save caller PCpop {r1}bx lr+ENDPROC(perf_regs_load)
1.7.11.7
Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches.
It takes single argument as a pointer to the regs dump buffer and populates it with current registers values.
Signed-off-by: Jean Pihet jean.pihet@linaro.org Cc: Steve Capper steve.capper@linaro.org Cc: Corey Ashford cjashfor@linux.vnet.ibm.com Cc: Frederic Weisbecker fweisbec@gmail.com Cc: Ingo Molnar mingo@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Arnaldo Carvalho de Melo acme@ghostprotocols.net Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@redhat.com --- tools/perf/arch/arm/Makefile | 1 + tools/perf/arch/arm/include/perf_regs.h | 2 ++ tools/perf/arch/arm/tests/regs_load.S | 47 +++++++++++++++++++++++++++++++++ 3 files changed, 50 insertions(+) create mode 100644 tools/perf/arch/arm/tests/regs_load.S
diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 67e9b3d..9b8f87e 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -4,4 +4,5 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o endif diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h index 2a1cfde..1476ae7 100644 --- a/tools/perf/arch/arm/include/perf_regs.h +++ b/tools/perf/arch/arm/include/perf_regs.h @@ -5,6 +5,8 @@ #include "../../util/types.h" #include <asm/perf_regs.h>
+void perf_regs_load(u64 *regs); + #define PERF_REGS_MASK ((1ULL << PERF_REG_ARM_MAX) - 1) #define PERF_REG_IP PERF_REG_ARM_PC #define PERF_REG_SP PERF_REG_ARM_SP diff --git a/tools/perf/arch/arm/tests/regs_load.S b/tools/perf/arch/arm/tests/regs_load.S new file mode 100644 index 0000000..916d268 --- /dev/null +++ b/tools/perf/arch/arm/tests/regs_load.S @@ -0,0 +1,47 @@ +#include <linux/linkage.h> + +#define R0 0x00 +#define R1 0x08 +#define R2 0x10 +#define R3 0x18 +#define R4 0x20 +#define R5 0x28 +#define R6 0x30 +#define R7 0x38 +#define R8 0x40 +#define R9 0x48 +#define SL 0x50 +#define FP 0x58 +#define IP 0x60 +#define SP 0x68 +#define LR 0x70 +#define PC 0x78 + +@ Implementation of void perf_regs_load(u64 *regs); +@ +@ This functions fills in the 'regs' buffer from the actual registers values. +@ Note that the return value (i.e. caller values) of pc is retrieved +@ and stored, in order to skip the call to this function. + +.text +.type perf_regs_load,%function +ENTRY(perf_regs_load) + str r0, [r0, #R0] + str r1, [r0, #R1] + str r2, [r0, #R2] + str r3, [r0, #R3] + str r4, [r0, #R4] + str r5, [r0, #R5] + str r6, [r0, #R6] + str r7, [r0, #R7] + str r8, [r0, #R8] + str r9, [r0, #R9] + str sl, [r0, #SL] + str fp, [r0, #FP] + str ip, [r0, #IP] + str sp, [r0, #SP] + str lr, [r0, #LR] + str lr, [r0, #PC] @ Save caller PC + + bx lr +ENDPROC(perf_regs_load)
Hi Jean,
On Mon, Mar 03, 2014 at 09:53:21AM +0000, Jean Pihet wrote:
Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches.
It takes single argument as a pointer to the regs dump buffer and populates it with current registers values.
[...]
diff --git a/tools/perf/arch/arm/tests/regs_load.S b/tools/perf/arch/arm/tests/regs_load.S new file mode 100644 index 0000000..241c6df --- /dev/null +++ b/tools/perf/arch/arm/tests/regs_load.S @@ -0,0 +1,51 @@ +#include <linux/linkage.h>
+#define R0 0x00 +#define R1 0x08
Why are you using a 64-bit stride for 32-bit registers? (which prevents you from using stm later on).
+.text +.type perf_regs_load,%function +ENTRY(perf_regs_load)
- push {r1}
Do you only push r1 here so that you can do the stack arithmetic later? That doesn't make sense to me -- can't you str sp directly?
- str r0, [r0, #R0]
- str r1, [r0, #R1]
- str r2, [r0, #R2]
- str r3, [r0, #R3]
- str r4, [r0, #R4]
- str r5, [r0, #R5]
- str r6, [r0, #R6]
- str r7, [r0, #R7]
- str r8, [r0, #R8]
- str r9, [r0, #R9]
- str sl, [r0, #SL]
- str fp, [r0, #FP]
- str ip, [r0, #IP]
- add r1, sp, #4 @ Retrieve and save sp at entry time
- str r1, [r0, #SP]
- str lr, [r0, #LR]
- str lr, [r0, #PC] @ Save caller PC
This isn't necessarily the `caller PC' (depending on how you define it). It's the return address, which is probably (but not always) the instruction following the branch to this function.
Will
Hi Will,
On 4 March 2014 12:00, Will Deacon will.deacon@arm.com wrote:
Hi Jean,
On Mon, Mar 03, 2014 at 09:53:21AM +0000, Jean Pihet wrote:
Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches.
It takes single argument as a pointer to the regs dump buffer and populates it with current registers values.
[...]
diff --git a/tools/perf/arch/arm/tests/regs_load.S b/tools/perf/arch/arm/tests/regs_load.S new file mode 100644 index 0000000..241c6df --- /dev/null +++ b/tools/perf/arch/arm/tests/regs_load.S @@ -0,0 +1,51 @@ +#include <linux/linkage.h>
+#define R0 0x00 +#define R1 0x08
Why are you using a 64-bit stride for 32-bit registers? (which prevents you from using stm later on).
This is because perf internally uses a 64-bit array for the registers, cf. the function prototype in the comment above.
+.text +.type perf_regs_load,%function +ENTRY(perf_regs_load)
push {r1}Do you only push r1 here so that you can do the stack arithmetic later? That doesn't make sense to me -- can't you str sp directly?
Yes indeed! I submitted a new version yesterday with that change and a fix in the comments.
str r0, [r0, #R0]str r1, [r0, #R1]str r2, [r0, #R2]str r3, [r0, #R3]str r4, [r0, #R4]str r5, [r0, #R5]str r6, [r0, #R6]str r7, [r0, #R7]str r8, [r0, #R8]str r9, [r0, #R9]str sl, [r0, #SL]str fp, [r0, #FP]str ip, [r0, #IP]add r1, sp, #4 @ Retrieve and save sp at entry timestr r1, [r0, #SP]str lr, [r0, #LR]str lr, [r0, #PC] @ Save caller PCThis isn't necessarily the `caller PC' (depending on how you define it). It's the return address, which is probably (but not always) the instruction following the branch to this function.
Agreed. However the perf test code expects a registers buffer filled in with the caller's values. I can change the comment here, is that needed?
Thanks for reviewing! Jean
Will
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On Wed, Mar 05, 2014 at 02:17:00AM +0000, Jean Pihet wrote:
On 4 March 2014 12:00, Will Deacon will.deacon@arm.com wrote:
On Mon, Mar 03, 2014 at 09:53:21AM +0000, Jean Pihet wrote:
str lr, [r0, #PC] @ Save caller PCThis isn't necessarily the `caller PC' (depending on how you define it). It's the return address, which is probably (but not always) the instruction following the branch to this function.
Agreed. However the perf test code expects a registers buffer filled in with the caller's values. I can change the comment here, is that needed?
It depends what the perf test code really expects. At the moment, you're not providing it with anything consistent which doesn't sound correct.
What does it use the caller PC for?
Will
On Thu, Mar 06, 2014 at 11:33:15AM +0000, Will Deacon wrote:
On Wed, Mar 05, 2014 at 02:17:00AM +0000, Jean Pihet wrote:
On 4 March 2014 12:00, Will Deacon will.deacon@arm.com wrote:
On Mon, Mar 03, 2014 at 09:53:21AM +0000, Jean Pihet wrote:
str lr, [r0, #PC] @ Save caller PCThis isn't necessarily the `caller PC' (depending on how you define it). It's the return address, which is probably (but not always) the instruction following the branch to this function.
Agreed. However the perf test code expects a registers buffer filled in with the caller's values. I can change the comment here, is that needed?
It depends what the perf test code really expects. At the moment, you're not providing it with anything consistent which doesn't sound correct.
the code expects caller's PC. That is what the x86 test code expects from perf_regs_load. We take the return IP saved by call instruction:
ENTRY(perf_regs_load) ... movq 0(%rsp), %rax movq %rax, IP(%rdi) ...
jirka
HI Will, Steve,
On 6 March 2014 18:22, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Mar 06, 2014 at 11:33:15AM +0000, Will Deacon wrote:
On Wed, Mar 05, 2014 at 02:17:00AM +0000, Jean Pihet wrote:
On 4 March 2014 12:00, Will Deacon will.deacon@arm.com wrote:
On Mon, Mar 03, 2014 at 09:53:21AM +0000, Jean Pihet wrote:
str lr, [r0, #PC] @ Save caller PCThis isn't necessarily the `caller PC' (depending on how you define it). It's the return address, which is probably (but not always) the instruction following the branch to this function.
Agreed. However the perf test code expects a registers buffer filled in with the caller's values. I can change the comment here, is that needed?
It depends what the perf test code really expects. At the moment, you're not providing it with anything consistent which doesn't sound correct.
the code expects caller's PC. That is what the x86 test code expects from perf_regs_load. We take the return IP saved by call instruction:
ENTRY(perf_regs_load) ... movq 0(%rsp), %rax movq %rax, IP(%rdi) ...
jirka
The perf built-in test code expects the caller PC to do the unwinding from. Does that sound correct to you?
Do you want me to add a note like this one (as done in the upcoming aarch64 patches, to be submitted asap after testing): " /* * Implementation of void perf_regs_load(u64 *regs); * * This functions fills in the 'regs' buffer from the actual registers values. * * Notes: * 1. the return value of the pc is retrieved from lr and stored, in order * to skip the call to this function, * 2. the current value of lr is merely retrieved and stored because the * value before the call to this function is unknown at this time; it will * be unwound from the dwarf information in unwind__get_entries. */ "
Please let me know how to make this better.
Regards, Jean
On Tue, Mar 11, 2014 at 06:25:11PM +0000, Jean Pihet wrote:
HI Will, Steve,
Hi Jean,
On 6 March 2014 18:22, Jiri Olsa jolsa@redhat.com wrote:
On Thu, Mar 06, 2014 at 11:33:15AM +0000, Will Deacon wrote:
On Wed, Mar 05, 2014 at 02:17:00AM +0000, Jean Pihet wrote:
On 4 March 2014 12:00, Will Deacon will.deacon@arm.com wrote:
On Mon, Mar 03, 2014 at 09:53:21AM +0000, Jean Pihet wrote:
str lr, [r0, #PC] @ Save caller PCThis isn't necessarily the `caller PC' (depending on how you define it). It's the return address, which is probably (but not always) the instruction following the branch to this function.
Agreed. However the perf test code expects a registers buffer filled in with the caller's values. I can change the comment here, is that needed?
It depends what the perf test code really expects. At the moment, you're not providing it with anything consistent which doesn't sound correct.
the code expects caller's PC. That is what the x86 test code expects from perf_regs_load. We take the return IP saved by call instruction:
ENTRY(perf_regs_load) ... movq 0(%rsp), %rax movq %rax, IP(%rdi) ...
jirka
The perf built-in test code expects the caller PC to do the unwinding from. Does that sound correct to you?
Yes, but we're not necessarily providing that in your code. We're providing the return address, which could be different (e.g., if this was a tail call).
Do you want me to add a note like this one (as done in the upcoming aarch64 patches, to be submitted asap after testing): " /*
- Implementation of void perf_regs_load(u64 *regs);
- This functions fills in the 'regs' buffer from the actual registers values.
- Notes:
- the return value of the pc is retrieved from lr and stored, in order
- to skip the call to this function,
- the current value of lr is merely retrieved and stored because the
- value before the call to this function is unknown at this time; it will
- be unwound from the dwarf information in unwind__get_entries.
*/ "
I think the main thing is that your code may well work for this specific test case (and perhaps that's good enough) but we should be clear about the assumptions you're making.
Will
Adding dwarf unwind test, that setups live machine data over the perf test thread and does the remote unwind.
Need to use -fno-optimize-sibling-calls for test compilation, otherwise 'krava_*' function calls are optimized into jumps and ommited from the stack unwind.
So far it was enabled only for x86.
Cc: Jiri Olsa jolsa@redhat.com Cc: Corey Ashford cjashfor@linux.vnet.ibm.com Cc: Frederic Weisbecker fweisbec@gmail.com Cc: Ingo Molnar mingo@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Arnaldo Carvalho de Melo acme@ghostprotocols.net Cc: David Ahern dsahern@gmail.com Signed-off-by: Jean Pihet jean.pihet@linaro.org --- tools/perf/Makefile.perf | 2 +- tools/perf/arch/arm/Makefile | 1 + tools/perf/arch/arm/include/perf_regs.h | 3 ++ tools/perf/arch/arm/tests/dwarf-unwind.c | 59 ++++++++++++++++++++++++++++++++ tools/perf/tests/builtin-test.c | 2 +- tools/perf/tests/tests.h | 2 +- 6 files changed, 66 insertions(+), 3 deletions(-) create mode 100644 tools/perf/arch/arm/tests/dwarf-unwind.c
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf index 50d875d..f281c4f 100644 --- a/tools/perf/Makefile.perf +++ b/tools/perf/Makefile.perf @@ -410,7 +410,7 @@ LIB_OBJS += $(OUTPUT)tests/code-reading.o LIB_OBJS += $(OUTPUT)tests/sample-parsing.o LIB_OBJS += $(OUTPUT)tests/parse-no-sample-id-all.o ifndef NO_DWARF_UNWIND -ifeq ($(ARCH),x86) +ifeq ($(ARCH),$(filter $(ARCH),x86 arm)) LIB_OBJS += $(OUTPUT)tests/dwarf-unwind.o endif endif diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 9b8f87e..221f21d 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -5,4 +5,5 @@ endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/dwarf-unwind.o endif diff --git a/tools/perf/arch/arm/include/perf_regs.h b/tools/perf/arch/arm/include/perf_regs.h index 1476ae7..c2cefff 100644 --- a/tools/perf/arch/arm/include/perf_regs.h +++ b/tools/perf/arch/arm/include/perf_regs.h @@ -8,6 +8,9 @@ void perf_regs_load(u64 *regs);
#define PERF_REGS_MASK ((1ULL << PERF_REG_ARM_MAX) - 1) +#define PERF_REGS_MAX PERF_REG_ARM_MAX +#define PERF_SAMPLE_REGS_ABI PERF_SAMPLE_REGS_ABI_32 + #define PERF_REG_IP PERF_REG_ARM_PC #define PERF_REG_SP PERF_REG_ARM_SP
diff --git a/tools/perf/arch/arm/tests/dwarf-unwind.c b/tools/perf/arch/arm/tests/dwarf-unwind.c new file mode 100644 index 0000000..87362f7 --- /dev/null +++ b/tools/perf/arch/arm/tests/dwarf-unwind.c @@ -0,0 +1,59 @@ +#include <string.h> +#include "perf_regs.h" +#include "thread.h" +#include "map.h" +#include "event.h" +#include "tests/tests.h" + +#define STACK_SIZE 8192 + +static int sample_ustack(struct perf_sample *sample, + struct thread *thread, u64 *regs) +{ + struct stack_dump *stack = &sample->user_stack; + struct map *map; + unsigned long sp; + u64 stack_size, *buf; + + buf = malloc(STACK_SIZE); + if (!buf) { + pr_debug("failed to allocate sample uregs data\n"); + return -1; + } + + sp = (unsigned long) regs[PERF_REG_ARM_SP]; + + map = map_groups__find(&thread->mg, MAP__FUNCTION, (u64) sp); + if (!map) { + pr_debug("failed to get stack map\n"); + return -1; + } + + stack_size = map->end - sp; + stack_size = stack_size > STACK_SIZE ? STACK_SIZE : stack_size; + + memcpy(buf, (void *) sp, stack_size); + stack->data = (char *) buf; + stack->size = stack_size; + return 0; +} + +int test__arch_unwind_sample(struct perf_sample *sample, + struct thread *thread) +{ + struct regs_dump *regs = &sample->user_regs; + u64 *buf; + + buf = calloc(1, sizeof(u64) * PERF_REGS_MAX); + if (!buf) { + pr_debug("failed to allocate sample uregs data\n"); + return -1; + } + + perf_regs_load(buf); + regs->abi = PERF_SAMPLE_REGS_ABI; + regs->regs = buf; + regs->mask = PERF_REGS_MASK; + + return sample_ustack(sample, thread, buf); +} diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index b11bf8a..167d527 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -115,7 +115,7 @@ static struct test { .desc = "Test parsing with no sample_id_all bit set", .func = test__parse_no_sample_id_all, }, -#if defined(__x86_64__) || defined(__i386__) +#if defined(__x86_64__) || defined(__i386__) || defined(__arm__) #ifdef HAVE_DWARF_UNWIND_SUPPORT { .desc = "Test dwarf unwind", diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index a24795c..0c89cfe 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -42,7 +42,7 @@ int test__keep_tracking(void); int test__parse_no_sample_id_all(void); int test__dwarf_unwind(void);
-#if defined(__x86_64__) || defined(__i386__) +#if defined(__x86_64__) || defined(__i386__) || defined(__arm__) #ifdef HAVE_DWARF_UNWIND_SUPPORT struct thread; struct perf_sample;
Adding libdw DWARF post unwind support, which is part of elfutils-devel/libdw-dev package from version 0.158.
The new code is contained in unwin-libdw.c object, and implements unwind__get_entries unwind interface function.
Signed-off-by: Jean Pihet jean.pihet@linaro.org Cc: Jiri Olsa jolsa@redhat.com Cc: Corey Ashford cjashfor@linux.vnet.ibm.com Cc: Frederic Weisbecker fweisbec@gmail.com Cc: Ingo Molnar mingo@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Arnaldo Carvalho de Melo acme@ghostprotocols.net Cc: David Ahern dsahern@gmail.com --- tools/perf/arch/arm/Makefile | 5 +++++ tools/perf/arch/arm/util/unwind-libdw.c | 36 +++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) create mode 100644 tools/perf/arch/arm/util/unwind-libdw.c
diff --git a/tools/perf/arch/arm/Makefile b/tools/perf/arch/arm/Makefile index 221f21d..09d6215 100644 --- a/tools/perf/arch/arm/Makefile +++ b/tools/perf/arch/arm/Makefile @@ -4,6 +4,11 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o +endif +ifndef NO_LIBDW_DWARF_UNWIND +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libdw.o +endif +ifndef NO_DWARF_UNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/dwarf-unwind.o endif diff --git a/tools/perf/arch/arm/util/unwind-libdw.c b/tools/perf/arch/arm/util/unwind-libdw.c new file mode 100644 index 0000000..b4176c6 --- /dev/null +++ b/tools/perf/arch/arm/util/unwind-libdw.c @@ -0,0 +1,36 @@ +#include <elfutils/libdwfl.h> +#include "../../util/unwind-libdw.h" +#include "../../util/perf_regs.h" + +bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +{ + struct unwind_info *ui = arg; + struct regs_dump *user_regs = &ui->sample->user_regs; + Dwarf_Word dwarf_regs[PERF_REG_ARM_MAX]; + +#define REG(r) ({ \ + Dwarf_Word val = 0; \ + perf_reg_value(&val, user_regs, PERF_REG_ARM_##r); \ + val; \ +}) + + dwarf_regs[0] = REG(R0); + dwarf_regs[1] = REG(R1); + dwarf_regs[2] = REG(R2); + dwarf_regs[3] = REG(R3); + dwarf_regs[4] = REG(R4); + dwarf_regs[5] = REG(R5); + dwarf_regs[6] = REG(R6); + dwarf_regs[7] = REG(R7); + dwarf_regs[8] = REG(R8); + dwarf_regs[9] = REG(R9); + dwarf_regs[10] = REG(R10); + dwarf_regs[11] = REG(FP); + dwarf_regs[12] = REG(IP); + dwarf_regs[13] = REG(SP); + dwarf_regs[14] = REG(LR); + dwarf_regs[15] = REG(PC); + + return dwfl_thread_state_registers(thread, 0, PERF_REG_ARM_MAX, + dwarf_regs); +}
Hi,
Here are some notes about the performance improvement and the test usage.
Jiri, do you need these notes in the one of commit description?
1. Using libdw vs libunwind on ARMv7
The performance gain is (more than) significant: >800%.
I did not profile perf itself ;-p just did a timing measurement. The benchmark has been run multiple times with different perf.data sizes. The results are consistent across the tests runs.
Usage: ./tools/perf/perf record --call-graph dwarf -- ../../libunwind/test_app/stress_bt time ./tools/perf/perf report --stdio > /dev/null 2>&1
Platform: Quad-core marvell XP370. perf runs on 1 cpu
Perf data size: 304MB libunwind libdw improvement real 9m31.577s 1m13.052s 782% user 5m33.020s 1m2.910s 529% sys 3m57.770s 0m10.090s 2356%
2. unwind test usage perf test list gives the list of supported tests. In this case the test #23 is dwarf unwinding:
./tools/perf/perf test 23 23: Test dwarf unwind : Ok
Regards, Jean
On 3 March 2014 10:53, Jean Pihet jean.pihet@linaro.org wrote:
Adding libdw DWARF post unwind support, which is part of elfutils-devel/libdw-dev package from version 0.158.
Also includes the test suite for dwarf unwinding, by adding the arch specific test code and the perf_regs_load function.
Jean Pihet (3): perf tests: Introduce perf_regs_load function on ARM perf tests: Add dwarf unwind test on ARM perf tools: Add libdw DWARF post unwind support for ARM
tools/perf/Makefile.perf | 2 +- tools/perf/arch/arm/Makefile | 7 ++++ tools/perf/arch/arm/include/perf_regs.h | 5 +++ tools/perf/arch/arm/tests/dwarf-unwind.c | 59 ++++++++++++++++++++++++++++++++ tools/perf/arch/arm/tests/regs_load.S | 51 +++++++++++++++++++++++++++ tools/perf/arch/arm/util/unwind-libdw.c | 36 +++++++++++++++++++ tools/perf/tests/builtin-test.c | 2 +- tools/perf/tests/tests.h | 2 +- 8 files changed, 161 insertions(+), 3 deletions(-) create mode 100644 tools/perf/arch/arm/tests/dwarf-unwind.c create mode 100644 tools/perf/arch/arm/tests/regs_load.S create mode 100644 tools/perf/arch/arm/util/unwind-libdw.c
- Rebased on latest acme/perf/core git tree,
- Tested on quad-core ARMv7 machine
-- 1.7.11.7
On Tue, Mar 04, 2014 at 02:24:37AM +0100, Jean Pihet wrote:
Hi,
Here are some notes about the performance improvement and the test usage.
Jiri, do you need these notes in the one of commit description?
- Using libdw vs libunwind on ARMv7
The performance gain is (more than) significant: >800%.
I dont mind.. but 800% would look just great in changelog ;-)
jirka
I did not profile perf itself ;-p just did a timing measurement. The benchmark has been run multiple times with different perf.data sizes. The results are consistent across the tests runs.
Usage: ./tools/perf/perf record --call-graph dwarf -- ../../libunwind/test_app/stress_bt time ./tools/perf/perf report --stdio > /dev/null 2>&1
Platform: Quad-core marvell XP370. perf runs on 1 cpu
Perf data size: 304MB libunwind libdw improvement real 9m31.577s 1m13.052s 782% user 5m33.020s 1m2.910s 529% sys 3m57.770s 0m10.090s 2356%
- unwind test usage
perf test list gives the list of supported tests. In this case the test #23 is dwarf unwinding:
./tools/perf/perf test 23 23: Test dwarf unwind : Ok
Regards, Jean
On 3 March 2014 10:53, Jean Pihet jean.pihet@linaro.org wrote:
Adding libdw DWARF post unwind support, which is part of elfutils-devel/libdw-dev package from version 0.158.
Also includes the test suite for dwarf unwinding, by adding the arch specific test code and the perf_regs_load function.
Jean Pihet (3): perf tests: Introduce perf_regs_load function on ARM perf tests: Add dwarf unwind test on ARM perf tools: Add libdw DWARF post unwind support for ARM
tools/perf/Makefile.perf | 2 +- tools/perf/arch/arm/Makefile | 7 ++++ tools/perf/arch/arm/include/perf_regs.h | 5 +++ tools/perf/arch/arm/tests/dwarf-unwind.c | 59 ++++++++++++++++++++++++++++++++ tools/perf/arch/arm/tests/regs_load.S | 51 +++++++++++++++++++++++++++ tools/perf/arch/arm/util/unwind-libdw.c | 36 +++++++++++++++++++ tools/perf/tests/builtin-test.c | 2 +- tools/perf/tests/tests.h | 2 +- 8 files changed, 161 insertions(+), 3 deletions(-) create mode 100644 tools/perf/arch/arm/tests/dwarf-unwind.c create mode 100644 tools/perf/arch/arm/tests/regs_load.S create mode 100644 tools/perf/arch/arm/util/unwind-libdw.c
- Rebased on latest acme/perf/core git tree,
- Tested on quad-core ARMv7 machine
-- 1.7.11.7
On Tue, Mar 04, 2014 at 02:24:37AM +0100, Jean Pihet wrote:
Hi,
Here are some notes about the performance improvement and the test usage.
Jiri, do you need these notes in the one of commit description?
- Using libdw vs libunwind on ARMv7
The performance gain is (more than) significant: >800%.
I did not profile perf itself ;-p just did a timing measurement. The benchmark has been run multiple times with different perf.data sizes. The results are consistent across the tests runs.
Usage: ./tools/perf/perf record --call-graph dwarf -- ../../libunwind/test_app/stress_bt time ./tools/perf/perf report --stdio > /dev/null 2>&1
Platform: Quad-core marvell XP370. perf runs on 1 cpu
Perf data size: 304MB libunwind libdw improvement real 9m31.577s 1m13.052s 782% user 5m33.020s 1m2.910s 529% sys 3m57.770s 0m10.090s 2356%
- unwind test usage
perf test list gives the list of supported tests. In this case the test #23 is dwarf unwinding:
./tools/perf/perf test 23 23: Test dwarf unwind : Ok
Regards, Jean
I can't speak for the arm specific stuff, but generally it fits and looks ok (and does not break the x86 build)
also.. who wouldn't ack 800% speed improvement ;-)
Acked-by: Jiri Olsa jolsa@redhat.com
thanks, jirka
linaro-kernel@lists.linaro.org
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Jean Pihet -
Jiri Olsa -
Will Deacon