Messages in this thread | | | From | Guo Ren <> | Date | Sun, 20 Nov 2022 12:26:28 +0800 | Subject | Re: [PATCH v3 0/2] riscv/ftrace: make function graph use ftrace directly |
| |
On Sat, Nov 19, 2022 at 1:32 AM Song Shuai <suagrfillet@gmail.com> wrote: > > 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. > > This series of patches makes function graph use ftrace directly for riscv. > > If FTRACE_WITH_REGS isn't defined, ftrace_caller keeps ftrace_graph_call > so that it can be replaced with the calling of prepare_ftrace_return by > the enable/disable helper. > > As for defining FTRACE_WITH_REGS, ftrace_caller is adjusted to save the > necessary regs against the pt_regs layout, so it can reasonably call the > graph_ops::func function - ftrace_graph_func. And ftrace_graph_[regs]_call > and its enable/disable helper aren't needed. > > The tests generated by CONFIG_FTRACE_STARTUP_TEST have passed in the local > qemu-system-riscv64 virt machine. The following is the log during startup. > > ``` > Nov 15 03:07:13 stage4 kernel: Testing tracer function: PASSED > Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace: PASSED > Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #1: > Nov 15 03:07:13 stage4 kernel: (1 0 1 0 0) > Nov 15 03:07:13 stage4 kernel: (1 1 2 0 0) > Nov 15 03:07:13 stage4 kernel: (2 1 3 0 365) > Nov 15 03:07:13 stage4 kernel: (2 2 4 0 399) > Nov 15 03:07:13 stage4 kernel: (3 2 4 0 146071) > Nov 15 03:07:13 stage4 kernel: (3 3 5 0 146105) PASSED > Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #2: > Nov 15 03:07:13 stage4 kernel: (1 0 1 589 0) > Nov 15 03:07:13 stage4 kernel: (1 1 2 635 0) > Nov 15 03:07:13 stage4 kernel: (2 1 3 1 2) > Nov 15 03:07:13 stage4 kernel: (2 2 4 125 126) > Nov 15 03:07:13 stage4 kernel: (3 2 4 146001 146078) > Nov 15 03:07:13 stage4 kernel: (3 3 5 146035 146112) PASSED > Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion: PASSED > Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion safe: PASSED > Nov 15 03:07:13 stage4 kernel: Testing ftrace regs: PASSED > Nov 15 03:07:13 stage4 kernel: Testing tracer nop: PASSED > Nov 15 03:07:13 stage4 kernel: Testing tracer irqsoff: PASSED > Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup: > Nov 15 03:07:13 stage4 kernel: sched: DL replenish lagged too much > Nov 15 03:07:13 stage4 kernel: PASSED > Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_rt: PASSED > Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_dl: PASSED > Nov 15 03:07:13 stage4 kernel: Testing tracer function_graph: PASSED > ``` > > Note that the changes of mcount-dyn.S conflicts with this unmerged > commit (riscv: entry: consolidate general regs saving/restoring). > https://lore.kernel.org/linux-riscv/20221103075047.1634923-15-guoren@kernel.org > > Changes since v2: > - line up the comments [Andrew] > - rename SAVE_ALL as SAVE_ABI_REGS [Guo Ren] > - consolidate the modifications of mcount-dyn.S into one patch [Guo Ren] > - adapt this series based on [riscv: ftrace: Fixup ftrace detour code][1] [Guo Ren] Tested-by: Guo Ren <guoren@kernel.org>
https://github.com/guoren83/linux/tree/ftrace_fixup_v3
> > [1]: https://lore.kernel.org/linux-riscv/20220921034910.3142465-1-guoren@kernel.org/ > v2 Link: https://lore.kernel.org/linux-riscv/20221116031305.286634-1-suagrfillet@gmail.com/ > > Changes since v1: > - fix the checkpatch warnings in patch 1 > v1 Link: https://lore.kernel.org/linux-riscv/20221115061525.112757-1-suagrfillet@gmail.com > > Song Shuai (2): > riscv/ftrace: add ftrace_graph_func > riscv/ftrace: make ftrace_caller call ftrace_graph_func > > arch/riscv/include/asm/ftrace.h | 13 ++- > arch/riscv/kernel/ftrace.c | 30 +++---- > arch/riscv/kernel/mcount-dyn.S | 143 +++++++++++++++++++++++--------- > 3 files changed, 129 insertions(+), 57 deletions(-) > > -- > 2.20.1 >
-- Best Regards Guo Ren
| |