Age | Commit message (Collapse) | Author | Files | Lines | |
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2019-10-10 | perf tools: Avoid 'sample_reg_masks' being const + weak | Ian Rogers | 2 | -0/+8 | |
Being const + weak breaks with some compilers that constant-propagate from the weak symbol. This behavior is outside of the specification, but in LLVM is chosen to match GCC's behavior. LLVM's implementation was set in this patch: https://github.com/llvm/llvm-project/commit/f49573d1eedcf1e44893d5a062ac1b72c8419646 A const + weak symbol is set to be weak_odr: https://llvm.org/docs/LangRef.html ODR is one definition rule, and given there is one constant definition constant-propagation is possible. It is possible to get this code to miscompile with LLVM when applying link time optimization. As compilers become more aggressive, this is likely to break in more instances. Move the definition of sample_reg_masks to the conditional part of perf_regs.h and guard usage with HAVE_PERF_REGS_SUPPORT. This avoids the weak symbol. Fix an issue when HAVE_PERF_REGS_SUPPORT isn't defined from patch v1. In v3, add perf_regs.c for architectures that HAVE_PERF_REGS_SUPPORT but don't declare sample_regs_masks. Further notes: Jiri asked: "Is this just a precaution or you actualy saw some breakage?" Ian answered: "We saw a breakage with clang with thinlto enabled for linking. Our compiler team had recently seen, and were surprised by, a similar issue and were able to dig out the weak ODR issue." Signed-off-by: Ian Rogers <[email protected]> Reviewed-by: Nick Desaulniers <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Albert Ou <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Budankov <[email protected]> Cc: Andi Kleen <[email protected]> Cc: [email protected] Cc: Guo Ren <[email protected]> Cc: Kan Liang <[email protected]> Cc: [email protected] Cc: Mao Han <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Palmer Dabbelt <[email protected]> Cc: Paul Walmsley <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> | |||||
2019-07-01 | perf annotate: Add csky support | Mao Han | 1 | -0/+48 | |
This patch add basic arch initialization and instruction associate support for the csky CPU architecture. E.g.: $ perf annotate --stdio2 Samples: 161 of event 'cpu-clock:pppH', 4000 Hz, Event count (approx.): 40250000, [percent: local period] test_4() /usr/lib/perf-test/callchain_test Percent Disassembly of section .text: 00008420 <test_4>: test_4(): subi sp, sp, 4 st.w r8, (sp, 0x0) mov r8, sp subi sp, sp, 8 subi r3, r8, 4 movi r2, 0 st.w r2, (r3, 0x0) ↓ br 2e 100.00 14: subi r3, r8, 4 ld.w r2, (r3, 0x0) subi r3, r8, 8 st.w r2, (r3, 0x0) subi r3, r8, 4 ld.w r3, (r3, 0x0) addi r2, r3, 1 subi r3, r8, 4 st.w r2, (r3, 0x0) 2e: subi r3, r8, 4 ld.w r2, (r3, 0x0) lrw r3, 0x98967f // 8598 <main+0x28> cmplt r3, r2 ↑ bf 14 mov r0, r0 mov r0, r0 mov sp, r8 ld.w r8, (sp, 0x0) addi sp, sp, 4 ← rts Signed-off-by: Mao Han <[email protected]> Acked-by: Guo Ren <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/d874d7782d9acdad5d98f2f5c4a6fb26fbe41c5d.1561531557.git.han_mao@c-sky.com Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> | |||||
2019-05-21 | treewide: Add SPDX license identifier - Makefile/Kconfig | Thomas Gleixner | 1 | -0/+1 | |
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> | |||||
2019-05-09 | csky: Add support for perf unwind-libdw | Mao Han | 6 | -0/+232 | |
This patch add support for DWARF register mappings and libdw registers initialization, which is used by perf callchain analyzing, eg: perf record --call-graph=dwarf <COMMAND> Here is elfutils csky backend patch set: https://sourceware.org/ml/elfutils-devel/2019-q2/msg00007.html Signed-off-by: Mao Han <[email protected]> Signed-off-by: Guo Ren <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Arnd Bergmann <[email protected]> |