Messages in this thread | | | From | Song Shuai <> | Date | Tue, 16 May 2023 09:50:47 +0000 | Subject | Re: [PATCH V10 0/4] riscv: Optimize function trace |
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Song Shuai <suagrfillet@gmail.com> 于2023年5月11日周四 09:32写道:
> > Changes in v10: > > - add Acked-by from Björn Töpel in patch 2 and patch 4 > - replace `move` with `mv` in patch3 > - prettify patch 2/4 with proper tabs > > You can directly try it with: > > https://github.com/sugarfillet/linux/tree/6.4-rc1-rv-ftrace-v10 > > Hi, plamer: This series is ready for its acceptance, you can pick it up.
> This series optimizes function trace. The first 3 independent > patches has been picked in the V7 version of this series, the > subsequent version continues the following 4 patches: > > select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1] (patch 1) > ========================================================== > > In RISC-V, -fpatchable-function-entry option is used to support > dynamic ftrace in this commit afc76b8b8011 ("riscv: Using > PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount > don't have to be called to create the __mcount_loc section before > the vmlinux linking. > > Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell > Makefile not to run recordmcount. > > Make function graph use ftrace directly [2] (patch 2) > ======================================================== > > In RISC-V architecture, when we enable the ftrace_graph tracer on some > functions, the function tracings on other functions will suffer extra > graph tracing work. In essence, graph_ops isn't limited by its func_hash > due to the global ftrace_graph_[regs]_call label. That should be > corrected. > > What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function > graph use ftrace directly") that uses graph_ops::func function to > install return_hooker and makes the function called against its > func_hash. > > Add WITH_DIRECT_CALLS support [3] (patch 3, 4) > ============================================== > > This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V. > SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included > here as the samples for testing DIRECT_CALLS related interface. > > First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide > register_ftrace_direct[_multi] interfaces allowing user to register > the customed trampoline (direct_caller) as the mcount for one or > more target functions. And modify_ftrace_direct[_multi] are also > provided for modify direct_caller. > > At the same time, the samples in ./samples/ftrace/ can be built > as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT > and SAMPLE_FTRACE_DIRECT_MULTI selected. > > Second, to make the direct_caller and the other ftrace hooks > (eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary > register > are nominated to store the address of direct_caller in > ftrace_regs_caller. > After the setting of the address direct_caller by direct_ops->func and > the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to > by the `jr` inst. > > The series's old changes related these patches > ========================================== > > Changes in v9: > https://lore.kernel.org/linux-riscv/20230510101857.2953955-1-suagrfillet@gmail.com/ > > 1. add Acked-by from Björn Töpel in patch 1 > > 2. rebase patch2/patch3 on Linux v6.4-rc1 > > - patch 2: to make the `SAVE_ABI_REGS` configurable, revert the > modification of mcount-dyn.S from commit (45b32b946a97 "riscv: > entry: Consolidate general regs saving/restoring") > > - patch 3: to pass the trace_selftest, add the implement of > `ftrace_stub_direct_tramp` from commit (fee86a4ed536 "ftrace: > selftest: remove broken trace_direct_tramp") ; and fixup the context > conflict in Kconfig > > Changes in v8: > https://lore.kernel.org/linux-riscv/20230324033342.3177979-1-suagrfillet@gmail.com/ > - Fix incorrect address values in the 4nd patch > - Rebased on v6.3-rc2 > > Changes in v7: > https://lore.kernel.org/linux-riscv/20230112090603.1295340-1-guoren@kernel.org/ > - Fixup RESTORE_ABI_REGS by remove PT_T0(sp) overwrite. > - Add FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1] > - Fixup kconfig with HAVE_SAMPLE_FTRACE_DIRECT & > HAVE_SAMPLE_FTRACE_DIRECT_MULTI > > Changes in v6: > https://lore.kernel.org/linux-riscv/20230107133549.4192639-1-guoren@kernel.org/ > - Replace 8 with MCOUNT_INSN_SIZE > - Replace "REG_L a1, PT_RA(sp)" with "mv a1, ra" > - Add Evgenii Shatokhin comment > > Changes in v5: > https://lore.kernel.org/linux-riscv/20221208091244.203407-1-guoren@kernel.org/ > - Sort Kconfig entries in alphabetical order. > > Changes in v4: > https://lore.kernel.org/linux-riscv/20221129033230.255947-1-guoren@kernel.org/ > - Include [3] for maintenance. [Song Shuai] > > Changes in V3: > https://lore.kernel.org/linux-riscv/20221123153950.2911981-1-guoren@kernel.org/ > - Include [2] for maintenance. [Song Shuai] > > [1]: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t > [2]: https://lore.kernel.org/lkml/20221120084230.910152-1-suagrfillet@gmail.com/ > [3]: https://lore.kernel.org/linux-riscv/20221123142025.1504030-1-suagrfillet@gmail.com/ > > Song Shuai (4): > riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY > riscv: ftrace: Add ftrace_graph_func > riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support > samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] > > arch/riscv/Kconfig | 4 + > arch/riscv/include/asm/ftrace.h | 19 +- > arch/riscv/kernel/ftrace.c | 30 ++- > arch/riscv/kernel/mcount-dyn.S | 200 ++++++++++++++++---- > samples/ftrace/ftrace-direct-modify.c | 34 ++++ > samples/ftrace/ftrace-direct-multi-modify.c | 40 ++++ > samples/ftrace/ftrace-direct-multi.c | 24 +++ > samples/ftrace/ftrace-direct-too.c | 27 +++ > samples/ftrace/ftrace-direct.c | 23 +++ > 9 files changed, 345 insertions(+), 56 deletions(-) > > -- > 2.20.1 >
-- Thanks, Song
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