From: Kunwu Chan <[email protected]> Add the backend operations used by AUX trace-buffer PMUs, backend state to damon_perf_event, and stubs for configurations without AUX support.
Add CONFIG_DAMON_PERF_AUX for the ARM SPE transport and a separate CONFIG_DAMON_PERF_SPE_KUNIT_TEST option. The current transport requires ARM SPE to be built into the kernel; it remains independent of the optional observability counters and tracepoints. Co-developed-by: Lian Wang (ProcessMission) <[email protected]> Signed-off-by: Lian Wang (ProcessMission) <[email protected]> Signed-off-by: Kunwu Chan <[email protected]> --- include/linux/damon.h | 5 +++ mm/damon/Kconfig | 28 +++++++++++++++ mm/damon/perf/aux_backend.h | 72 +++++++++++++++++++++++++++++++++++++ 3 files changed, 105 insertions(+) create mode 100644 mm/damon/perf/aux_backend.h diff --git a/include/linux/damon.h b/include/linux/damon.h index c191c065b0e4..a27c5f6c459b 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -8,6 +8,7 @@ #ifndef _DAMON_H_ #define _DAMON_H_ +#include <linux/cpumask.h> #include <linux/math64.h> #include <linux/memcontrol.h> #include <linux/mutex.h> @@ -127,6 +128,7 @@ struct damon_target { enum damon_report_source { DAMON_REPORT_SRC_PERF_OVERFLOW = 0, /* overflow_handler (IBS, PEBS) */ DAMON_REPORT_SRC_PAGE_FAULT, /* damon_report_page_fault() */ + DAMON_REPORT_SRC_PERF_AUX, /* AUX trace-buffer backend */ }; /** @@ -538,6 +540,7 @@ struct damos_filter { struct damon_ctx; struct damon_target_lookup; struct damos; +struct damon_perf_backend_ops; /** * struct damos_walk_control - Control damos_walk(). @@ -1056,6 +1059,8 @@ struct damon_perf_event_attr { struct damon_perf_event { struct damon_perf_event_attr attr; void *priv; + const struct damon_perf_backend_ops *ops; + cpumask_t aux_cpumask; struct list_head list; struct hlist_node hlist_node; bool init_complete; diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig index 9fac286df124..e9fb62ec186f 100644 --- a/mm/damon/Kconfig +++ b/mm/damon/Kconfig @@ -149,4 +149,32 @@ config DAMON_PERF_OBSERVE If unsure, say N. + +config DAMON_PERF_AUX + bool "DAMON AUX trace-buffer backend support" + depends on DAMON + depends on PERF_EVENTS + depends on ARM_SPE_PMU=y + default n + help + Enable the functional AUX trace-buffer transport for DAMON perf + events. This provides backend selection and drain scheduling for + ARM SPE, which does not deliver samples through an overflow + callback. ARM SPE must be built into the kernel. + + This transport is independent of CONFIG_DAMON_PERF_OBSERVE. + + If unsure, say N. + +config DAMON_PERF_SPE_KUNIT_TEST + bool "Test the DAMON perf SPE parser" if !KUNIT_ALL_TESTS + depends on DAMON_PERF_AUX && KUNIT=y + default KUNIT_ALL_TESTS + help + Test the ARM SPE parser with byte-exact packet streams. The cases + cover valid records, truncation, alignment, error resynchronization + and consumed-length accounting. Results can be exposed through + debugfs when CONFIG_KUNIT_DEBUGFS is enabled. + + If unsure, say N. endmenu diff --git a/mm/damon/perf/aux_backend.h b/mm/damon/perf/aux_backend.h new file mode 100644 index 000000000000..70e6ac6771bc --- /dev/null +++ b/mm/damon/perf/aux_backend.h @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _DAMON_PERF_AUX_BACKEND_H +#define _DAMON_PERF_AUX_BACKEND_H + +#include <linux/bits.h> +#include <linux/errno.h> +#include <linux/perf_event.h> +#include <linux/types.h> + +struct damon_ctx; +struct damon_perf_event; + +/** + * struct damon_perf_backend_ops - PMU-specific AUX backend operations + * @name: Human-readable backend name. + * @flags: Bitmask of DAMON_PERF_BACKEND_* flags. + * @match_pmu: Return true when this backend claims @perf_event. + * @init: Allocate per-event, per-CPU resources. + * @cleanup: Release resources initialized for one CPU. + * @arm: Prepare the AUX producer before perf_event_enable(). + * @disarm: Quiesce backend state after perf_event_disable(). + * @drain: Parse pending AUX data into DAMON access reports. + * + * All callbacks run in process context. The caller serializes resource + * lifetime against CPU hotplug and invokes @drain only for CPUs recorded + * in damon_perf_event::aux_cpumask. + */ +struct damon_perf_backend_ops { + const char *name; + u32 flags; + bool (*match_pmu)(struct perf_event *perf_event); + int (*init)(struct damon_perf_event *event, int cpu, + struct perf_event *perf_event); + void (*cleanup)(struct damon_perf_event *event, int cpu); + int (*arm)(struct damon_perf_event *event, int cpu); + void (*disarm)(struct damon_perf_event *event, int cpu); + unsigned int (*drain)(struct damon_perf_event *event, int cpu); +}; + +#define DAMON_PERF_BACKEND_AUX BIT(0) + +#ifdef CONFIG_DAMON_PERF_AUX +void damon_perf_aux_drain(struct damon_ctx *ctx); +int damon_perf_aux_register_backend(const struct damon_perf_backend_ops *ops); +const struct damon_perf_backend_ops * +damon_perf_aux_find_backend(struct perf_event *perf_event); +void damon_perf_aux_select(struct damon_perf_event *event, + struct perf_event *perf_event); +#else +static inline void damon_perf_aux_drain(struct damon_ctx *ctx) +{ +} + +static inline int +damon_perf_aux_register_backend(const struct damon_perf_backend_ops *ops) +{ + return -EOPNOTSUPP; +} + +static inline const struct damon_perf_backend_ops * +damon_perf_aux_find_backend(struct perf_event *perf_event) +{ + return NULL; +} + +static inline void damon_perf_aux_select(struct damon_perf_event *event, + struct perf_event *perf_event) +{ +} +#endif + +#endif /* _DAMON_PERF_AUX_BACKEND_H */ -- 2.43.0
