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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
| commit | cf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch) | |
| tree | 757a3d280760c654767631cab5ad8af2d86d1848 /samples/ftrace/ftrace-ops.c | |
| download | linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.zip | |
Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij:
"Core changes:
- Use the non-blocking mux_state_try_select() in the generic MUX pin
control back-end
- Free pin maps on pinctrl_generic_to_map() failure in the core
helpers
New hardware pin control:
- Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC
(this is for the low power audio, LPASS = Low Power Audio SubSystem
portions)
- Upboard support on top of the Intel pin controller
- Apple T6030 and T6031 support (just compatible strings)
- Samsung Exynos 8855 SoC
- Mediatek MT6858 SoC
- Rockchip RK3308B and RV1106 SoCs
- Airoha EN7523 and AN7563 SoCs
Improvements:
- Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable
- Qualcomm improvements on top of the Qualcomm PDC (power domain
controller) irqchip improvements from tglx:s tree
- Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups
- The NPCM8xx driver has been put into shape fixing many pin and
group definitions
- Some non-urgent Tegra 264 pin assignments are fixed up
- Some non-urgent fixups to Airoha AN7581 and AN7583 registers and
pin assignments, missing features etc"
* tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits)
dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema
pinctrl: meson: sync some modify from A4
pinctrl: meson: a4: Add input enable pin configuration
pinctrl: realtek: rtd1625: remove unused group name spdif_sel
pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13
dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema
Revert "Merge branch 'ib-rsk7204' into devel"
pinctrl: rockchip: Add RV1106 pinctrl support
dt-bindings: pinctrl: rockchip: Add RV1106 compatible
pinctrl: rockchip: Decode drive strength in the get function
pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable
pinctrl: airoha: add support of an7563 SoC
dt-bindings: pinctrl: airoha: add support of an7563 pin controller
pinctrl: airoha: try to find chip scu node by phandle first
pinctrl: airoha: add support of en7523 SoC
dt-bindings: pinctrl: airoha: add support of en7523 pin controller
pinctrl: airoha: an7583: add support for olt pinmux
pinctrl: airoha: an7583: add support for pon_alt pinmux
pinctrl: airoha: an7583: add support for npu_uart pinmux
dt-bindings: pinctrl: airoha: an7583: add missed features
...
Diffstat (limited to 'samples/ftrace/ftrace-ops.c')
| -rw-r--r-- | samples/ftrace/ftrace-ops.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/samples/ftrace/ftrace-ops.c b/samples/ftrace/ftrace-ops.c new file mode 100644 index 000000000..8cae38d8b --- /dev/null +++ b/samples/ftrace/ftrace-ops.c @@ -0,0 +1,252 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/ftrace.h> +#include <linux/ktime.h> +#include <linux/module.h> + +#include <asm/barrier.h> + +/* + * Arbitrary large value chosen to be sufficiently large to minimize noise but + * sufficiently small to complete quickly. + */ +static unsigned int nr_function_calls = 100000; +module_param(nr_function_calls, uint, 0); +MODULE_PARM_DESC(nr_function_calls, "How many times to call the relevant tracee"); + +/* + * The number of ops associated with a call site affects whether a tracer can + * be called directly or whether it's necessary to go via the list func, which + * can be significantly more expensive. + */ +static unsigned int nr_ops_relevant = 1; +module_param(nr_ops_relevant, uint, 0); +MODULE_PARM_DESC(nr_ops_relevant, "How many ftrace_ops to associate with the relevant tracee"); + +/* + * On architectures where all call sites share the same trampoline, having + * tracers enabled for distinct functions can force the use of the list func + * and incur overhead for all call sites. + */ +static unsigned int nr_ops_irrelevant; +module_param(nr_ops_irrelevant, uint, 0); +MODULE_PARM_DESC(nr_ops_irrelevant, "How many ftrace_ops to associate with the irrelevant tracee"); + +/* + * On architectures with DYNAMIC_FTRACE_WITH_REGS, saving the full pt_regs can + * be more expensive than only saving the minimal necessary regs. + */ +static bool save_regs; +module_param(save_regs, bool, 0); +MODULE_PARM_DESC(save_regs, "Register ops with FTRACE_OPS_FL_SAVE_REGS (save all registers in the trampoline)"); + +static bool assist_recursion; +module_param(assist_recursion, bool, 0); +MODULE_PARM_DESC(assist_reursion, "Register ops with FTRACE_OPS_FL_RECURSION"); + +static bool assist_rcu; +module_param(assist_rcu, bool, 0); +MODULE_PARM_DESC(assist_reursion, "Register ops with FTRACE_OPS_FL_RCU"); + +/* + * By default, a trivial tracer is used which immediately returns to mimimize + * overhead. Sometimes a consistency check using a more expensive tracer is + * desireable. + */ +static bool check_count; +module_param(check_count, bool, 0); +MODULE_PARM_DESC(check_count, "Check that tracers are called the expected number of times\n"); + +/* + * Usually it's not interesting to leave the ops registered after the test + * runs, but sometimes it can be useful to leave them registered so that they + * can be inspected through the tracefs 'enabled_functions' file. + */ +static bool persist; +module_param(persist, bool, 0); +MODULE_PARM_DESC(persist, "Successfully load module and leave ftrace ops registered after test completes\n"); + +/* + * Marked as noinline to ensure that an out-of-line traceable copy is + * generated by the compiler. + * + * The barrier() ensures the compiler won't elide calls by determining there + * are no side-effects. + */ +static noinline void tracee_relevant(void) +{ + barrier(); +} + +/* + * Marked as noinline to ensure that an out-of-line traceable copy is + * generated by the compiler. + * + * The barrier() ensures the compiler won't elide calls by determining there + * are no side-effects. + */ +static noinline void tracee_irrelevant(void) +{ + barrier(); +} + +struct sample_ops { + struct ftrace_ops ops; + unsigned int count; +}; + +static void ops_func_nop(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, + struct ftrace_regs *fregs) +{ + /* do nothing */ +} + +static void ops_func_count(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, + struct ftrace_regs *fregs) +{ + struct sample_ops *self; + + self = container_of(op, struct sample_ops, ops); + self->count++; +} + +static struct sample_ops *ops_relevant; +static struct sample_ops *ops_irrelevant; + +static struct sample_ops *ops_alloc_init(void *tracee, ftrace_func_t func, + unsigned long flags, int nr) +{ + struct sample_ops *ops; + + ops = kcalloc(nr, sizeof(*ops), GFP_KERNEL); + if (WARN_ON_ONCE(!ops)) + return NULL; + + for (unsigned int i = 0; i < nr; i++) { + ops[i].ops.func = func; + ops[i].ops.flags = flags; + WARN_ON_ONCE(ftrace_set_filter_ip(&ops[i].ops, (unsigned long)tracee, 0, 0)); + WARN_ON_ONCE(register_ftrace_function(&ops[i].ops)); + } + + return ops; +} + +static void ops_destroy(struct sample_ops *ops, int nr) +{ + if (!ops) + return; + + for (unsigned int i = 0; i < nr; i++) { + WARN_ON_ONCE(unregister_ftrace_function(&ops[i].ops)); + ftrace_free_filter(&ops[i].ops); + } + + kfree(ops); +} + +static void ops_check(struct sample_ops *ops, int nr, + unsigned int expected_count) +{ + if (!ops || !check_count) + return; + + for (unsigned int i = 0; i < nr; i++) { + if (ops->count == expected_count) + continue; + pr_warn("Counter called %u times (expected %u)\n", + ops->count, expected_count); + } +} + +static ftrace_func_t tracer_relevant = ops_func_nop; +static ftrace_func_t tracer_irrelevant = ops_func_nop; + +static int __init ftrace_ops_sample_init(void) +{ + unsigned long flags = 0; + ktime_t start, end; + u64 period; + + if (!IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && save_regs) { + pr_info("this kernel does not support saving registers\n"); + save_regs = false; + } else if (save_regs) { + flags |= FTRACE_OPS_FL_SAVE_REGS; + } + + if (assist_recursion) + flags |= FTRACE_OPS_FL_RECURSION; + + if (assist_rcu) + flags |= FTRACE_OPS_FL_RCU; + + if (check_count) { + tracer_relevant = ops_func_count; + tracer_irrelevant = ops_func_count; + } + + pr_info("registering:\n" + " relevant ops: %u\n" + " tracee: %ps\n" + " tracer: %ps\n" + " irrelevant ops: %u\n" + " tracee: %ps\n" + " tracer: %ps\n" + " saving registers: %s\n" + " assist recursion: %s\n" + " assist RCU: %s\n", + nr_ops_relevant, tracee_relevant, tracer_relevant, + nr_ops_irrelevant, tracee_irrelevant, tracer_irrelevant, + save_regs ? "YES" : "NO", + assist_recursion ? "YES" : "NO", + assist_rcu ? "YES" : "NO"); + + ops_relevant = ops_alloc_init(tracee_relevant, tracer_relevant, + flags, nr_ops_relevant); + ops_irrelevant = ops_alloc_init(tracee_irrelevant, tracer_irrelevant, + flags, nr_ops_irrelevant); + + start = ktime_get(); + for (unsigned int i = 0; i < nr_function_calls; i++) + tracee_relevant(); + end = ktime_get(); + + ops_check(ops_relevant, nr_ops_relevant, nr_function_calls); + ops_check(ops_irrelevant, nr_ops_irrelevant, 0); + + period = ktime_to_ns(ktime_sub(end, start)); + + pr_info("Attempted %u calls to %ps in %lluns (%lluns / call)\n", + nr_function_calls, tracee_relevant, + period, nr_function_calls ? div_u64(period, nr_function_calls) : -1LL); + + if (persist) + return 0; + + ops_destroy(ops_relevant, nr_ops_relevant); + ops_destroy(ops_irrelevant, nr_ops_irrelevant); + + /* + * The benchmark completed successfully, but there's no reason to keep + * the module around. Return an error so the user doesn't have to + * manually unload the module. + */ + return -EINVAL; +} +module_init(ftrace_ops_sample_init); + +static void __exit ftrace_ops_sample_exit(void) +{ + ops_destroy(ops_relevant, nr_ops_relevant); + ops_destroy(ops_irrelevant, nr_ops_irrelevant); +} +module_exit(ftrace_ops_sample_exit); + +MODULE_AUTHOR("Mark Rutland"); +MODULE_DESCRIPTION("Example of using custom ftrace_ops"); +MODULE_LICENSE("GPL"); |
