[PATCH v1 00/11] perf script: Refactor branch flags for Arm SPE
Ian Rogers
irogers at google.com
Tue Feb 11 14:34:46 PST 2025
On Wed, Feb 5, 2025 at 4:16 AM Leo Yan <leo.yan at arm.com> wrote:
>
> This patch series refactors branch flags for support Arm SPE. The patch
> set is divided into two parts, the first part is for refactoring common
> code and the second part is for enabling Arm SPE.
>
> For refactoring branch flags, the sample flaghs are classified as branch
> types and events. A program branch type can be conditional branch,
> function call, return or expection taken. A branch event happens when
> taking a branch. This series combines branch types and the associated
> events to present a sample flag.
>
> The second part is to enable Arm SPE's sample flags for expressing
> branch types and events, and support branch stack.
>
> Patches 01 - 03 are to refactor branch types and branch events.
> Patches 04, 05 extend to support not-taken event.
>
> Patches 06 - 09 enables branch flags in Arm SPE. This allows to print
> out sample flags for samples.
>
> Patch 10 supports branch stack for Arm SPE. Patch 11 is an enhancement
> for PBT feature.
>
> Before:
> perf record -e arm_spe_0/load_filter=1,store_filter=1,branch_filter=1/ \
> -- ~/perf-c2c-usage-files/false_sharing.exe 1
> perf script --itrace=i1ibl -F,+flags,+addr,+brstack
> false_sharing.e 414489 [005] 775348.899294: 1 branch: jmp ffffc0fad9ef3d68 ffffc0fad98b2c68 search_cmp_ftr_reg+0x8 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899294: 1 instructions: jmp ffffc0fad9ef3d68 ffffc0fad98b2c68 search_cmp_ftr_reg+0x8 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899294: 1 branch: jmp ffffc0fad98b3708 ffffc0fad98b3704 get_arm64_ftr_reg+0x30 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899294: 1 instructions: jmp ffffc0fad98b3708 ffffc0fad98b3704 get_arm64_ftr_reg+0x30 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899297: 1 branch: br miss ffff8266da60 ffff8266dafc __sprintf_chk at plt+0xc (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0)
> false_sharing.e 414489 [005] 775348.899297: 1 instructions: br miss ffff8266da60 ffff8266dafc __sprintf_chk at plt+0xc (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0)
> false_sharing.e 414489 [005] 775348.899297: 1 branch: br miss ffff826a44ec ffff826a44e8 strcmp+0xa8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
> false_sharing.e 414489 [005] 775348.899297: 1 instructions: br miss ffff826a44ec ffff826a44e8 strcmp+0xa8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
> false_sharing.e 414489 [005] 775348.899298: 1 instructions: 0 ffffc0fadaad6124 mas_walk+0x274 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899300: 1 instructions: 0 ffffc0fad9b3d98c next_uptodate_folio+0x2a4 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899301: 1 instructions: 0 ffffc0fad98c3dcc __sync_icache_dcache+0x5c ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899301: 1 branch: jmp ffffc0fad9ba7f24 ffffc0fad9ba99c0 folio_add_file_rmap_ptes+0x48 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899301: 1 instructions: jmp ffffc0fad9ba7f24 ffffc0fad9ba99c0 folio_add_file_rmap_ptes+0x48 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899306: 1 instructions: 0 ffffc0fad9b3f184 filemap_map_pages+0x178 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899307: 1 branch: jmp ffffc0fad9b3d7b0 ffffc0fad9b3d7ac next_uptodate_folio+0xc4 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899307: 1 instructions: jmp ffffc0fad9b3d7b0 ffffc0fad9b3d7ac next_uptodate_folio+0xc4 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899307: 1 instructions: 0 ffffc0fad9b3d98c next_uptodate_folio+0x2a4 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899308: 1 branch: jmp ffffc0fad9ef3da4 ffffc0fad9ef3d70 bsearch+0x58 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899308: 1 instructions: jmp ffffc0fad9ef3da4 ffffc0fad9ef3d70 bsearch+0x58 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899310: 1 branch: jmp ffffc0fad98a2158 ffffc0fad98a159c el0t_64_sync+0x198 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899310: 1 instructions: jmp ffffc0fad98a2158 ffffc0fad98a159c el0t_64_sync+0x198 ([kernel.kallsyms])
> ...
>
> After:
> perf script --itrace=i1ibl -F,+flags,+addr,+brstack
> false_sharing.e 414489 [005] 775348.899294: 1 branch: return ffffc0fad9ef3d68 ffffc0fad98b2c68 search_cmp_ftr_reg+0x8 ([kernel.kallsyms]) 0xffffc0fad98b2c68 ([kernel.kallsyms])/0xffffc0fad9ef3d68 ([kernel.kallsyms])/P/-/-/5/RET/-
> false_sharing.e 414489 [005] 775348.899294: 1 instructions: return ffffc0fad9ef3d68 ffffc0fad98b2c68 search_cmp_ftr_reg+0x8 ([kernel.kallsyms]) 0xffffc0fad98b2c68 ([kernel.kallsyms])/0xffffc0fad9ef3d68 ([kernel.kallsyms])/P/-/-/5/RET/-
> false_sharing.e 414489 [005] 775348.899294: 1 branch: jcc/not_taken/ ffffc0fad98b3708 ffffc0fad98b3704 get_arm64_ftr_reg+0x30 ([kernel.kallsyms]) 0xffffc0fad98b3704 ([kernel.kallsyms])/0xffffc0fad98b3708 ([kernel.kallsyms])/PN/-/-/6/COND/-
> false_sharing.e 414489 [005] 775348.899294: 1 instructions: jcc/not_taken/ ffffc0fad98b3708 ffffc0fad98b3704 get_arm64_ftr_reg+0x30 ([kernel.kallsyms]) 0xffffc0fad98b3704 ([kernel.kallsyms])/0xffffc0fad98b3708 ([kernel.kallsyms])/PN/-/-/6/COND/-
> false_sharing.e 414489 [005] 775348.899297: 1 branch: return/miss/ ffff8266da60 ffff8266dafc __sprintf_chk at plt+0xc (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0) 0xffff8266dafc (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0)/0xffff8266da60 (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0)/M/-/-/12/RET/-
> false_sharing.e 414489 [005] 775348.899297: 1 instructions: return/miss/ ffff8266da60 ffff8266dafc __sprintf_chk at plt+0xc (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0) 0xffff8266dafc (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0)/0xffff8266da60 (/usr/lib/aarch64-linux-gnu/libnuma.so.1.0.0)/M/-/-/12/RET/-
> false_sharing.e 414489 [005] 775348.899297: 1 branch: jcc/miss,not_taken/ ffff826a44ec ffff826a44e8 strcmp+0xa8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so) 0xffff826a44e8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)/0xffff826a44ec (/usr/lib/aarch64-linux-gnu/ld-2.31.so)/MN/-/-/23/COND/-
> false_sharing.e 414489 [005] 775348.899297: 1 instructions: jcc/miss,not_taken/ ffff826a44ec ffff826a44e8 strcmp+0xa8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so) 0xffff826a44e8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)/0xffff826a44ec (/usr/lib/aarch64-linux-gnu/ld-2.31.so)/MN/-/-/23/COND/-
> false_sharing.e 414489 [005] 775348.899298: 1 instructions: 0 ffffc0fadaad6124 mas_walk+0x274 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899300: 1 instructions: 0 ffffc0fad9b3d98c next_uptodate_folio+0x2a4 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899301: 1 instructions: 0 ffffc0fad98c3dcc __sync_icache_dcache+0x5c ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899301: 1 branch: jmp ffffc0fad9ba7f24 ffffc0fad9ba99c0 folio_add_file_rmap_ptes+0x48 ([kernel.kallsyms]) 0xffffc0fad9ba99c0 ([kernel.kallsyms])/0xffffc0fad9ba7f24 ([kernel.kallsyms])/P/-/-/8//-
> false_sharing.e 414489 [005] 775348.899301: 1 instructions: jmp ffffc0fad9ba7f24 ffffc0fad9ba99c0 folio_add_file_rmap_ptes+0x48 ([kernel.kallsyms]) 0xffffc0fad9ba99c0 ([kernel.kallsyms])/0xffffc0fad9ba7f24 ([kernel.kallsyms])/P/-/-/8//-
> false_sharing.e 414489 [005] 775348.899306: 1 instructions: 0 ffffc0fad9b3f184 filemap_map_pages+0x178 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899307: 1 branch: jcc/not_taken/ ffffc0fad9b3d7b0 ffffc0fad9b3d7ac next_uptodate_folio+0xc4 ([kernel.kallsyms]) 0xffffc0fad9b3d7ac ([kernel.kallsyms])/0xffffc0fad9b3d7b0 ([kernel.kallsyms])/PN/-/-/15/COND/-
> false_sharing.e 414489 [005] 775348.899307: 1 instructions: jcc/not_taken/ ffffc0fad9b3d7b0 ffffc0fad9b3d7ac next_uptodate_folio+0xc4 ([kernel.kallsyms]) 0xffffc0fad9b3d7ac ([kernel.kallsyms])/0xffffc0fad9b3d7b0 ([kernel.kallsyms])/PN/-/-/15/COND/-
> false_sharing.e 414489 [005] 775348.899307: 1 instructions: 0 ffffc0fad9b3d98c next_uptodate_folio+0x2a4 ([kernel.kallsyms])
> false_sharing.e 414489 [005] 775348.899308: 1 branch: jcc ffffc0fad9ef3da4 ffffc0fad9ef3d70 bsearch+0x58 ([kernel.kallsyms]) 0xffffc0fad9ef3d70 ([kernel.kallsyms])/0xffffc0fad9ef3da4 ([kernel.kallsyms])/P/-/-/20/COND/-
> false_sharing.e 414489 [005] 775348.899308: 1 instructions: jcc ffffc0fad9ef3da4 ffffc0fad9ef3d70 bsearch+0x58 ([kernel.kallsyms]) 0xffffc0fad9ef3d70 ([kernel.kallsyms])/0xffffc0fad9ef3da4 ([kernel.kallsyms])/P/-/-/20/COND/-
> false_sharing.e 414489 [005] 775348.899310: 1 branch: jmp ffffc0fad98a2158 ffffc0fad98a159c el0t_64_sync+0x198 ([kernel.kallsyms]) 0xffffc0fad98a159c ([kernel.kallsyms])/0xffffc0fad98a2158 ([kernel.kallsyms])/P/-/-/5//-
> false_sharing.e 414489 [005] 775348.899310: 1 instructions: jmp ffffc0fad98a2158 ffffc0fad98a159c el0t_64_sync+0x198 ([kernel.kallsyms]) 0xffffc0fad98a159c ([kernel.kallsyms])/0xffffc0fad98a2158 ([kernel.kallsyms])/P/-/-/5//-
> ...
Reviewed-by: Ian Rogers <irogers at google.com>
Built and tested (on x86). A little strange patch 5 adds a new bit not
at the end, but "Sample parsing" test wasn't broken so looks like it
is good. I was surprised the use of value in the union:
```
struct branch_flags {
union {
u64 value;
struct {
u64 mispred:1;
u64 predicted:1;
...
```
didn't get broken. Perhaps there's an opportunity for additional tests.
Thanks,
Ian
> Leo Yan (11):
> perf script: Make printing flags reliable
> perf script: Refactor sample_flags_to_name() function
> perf script: Separate events from branch types
> perf script: Add not taken event for branches
> perf script: Add not taken event for branch stack
> perf arm-spe: Extend branch operations
> perf arm-spe: Decode transactional event
> perf arm-spe: Fill branch operations and events to record
> perf arm-spe: Set sample flags with supplement info
> perf arm-spe: Add branch stack
> perf arm-spe: Support previous branch target (PBT) address
>
> tools/perf/builtin-script.c | 30 ++--
> .../util/arm-spe-decoder/arm-spe-decoder.c | 23 ++-
> .../util/arm-spe-decoder/arm-spe-decoder.h | 11 +-
> .../arm-spe-decoder/arm-spe-pkt-decoder.c | 14 +-
> .../arm-spe-decoder/arm-spe-pkt-decoder.h | 12 +-
> tools/perf/util/arm-spe.c | 135 ++++++++++++++++++
> tools/perf/util/branch.h | 3 +-
> tools/perf/util/event.h | 12 +-
> tools/perf/util/trace-event-scripting.c | 116 +++++++++++----
> tools/perf/util/trace-event.h | 2 +
> 10 files changed, 307 insertions(+), 51 deletions(-)
>
> --
> 2.34.1
>
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