perf: Add ability to sample machine state on interrupt

Enable capture of interrupted machine state for each sample. Registers to sample are passed per event in the sample_regs_intr bitmask. To sample interrupt machine state, the PERF_SAMPLE_INTR_REGS must be passed in sample_type. The list of available registers is arch dependent and provided by asm/perf_regs.h Registers are laid out as u64 in the order of the bit order of sample_intr_regs. This patch also adds a new ABI version PERF_ATTR_SIZE_VER4 because we extend the perf_event_attr struct with a new u64 field.

Stephane Eranian committed 12 years ago

Commit 60e23641 parent af4bdcf3 files · +63 −5Browse files

Showing the changes to include/uapi/linux (1 of 3 files). Show all

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include/uapi/linux/perf_event.h+14−1

 	PERF_SAMPLE_DATA_SRC			= 1U << 15,
 	PERF_SAMPLE_IDENTIFIER			= 1U << 16,
 	PERF_SAMPLE_TRANSACTION			= 1U << 17,
+	PERF_SAMPLE_REGS_INTR			= 1U << 18,
-	PERF_SAMPLE_MAX = 1U << 18,		/* non-ABI */
+	PERF_SAMPLE_MAX = 1U << 19,		/* non-ABI */
 };
 /*
 #define PERF_ATTR_SIZE_VER2	80	/* add: branch_sample_type */
 #define PERF_ATTR_SIZE_VER3	96	/* add: sample_regs_user */
 					/* add: sample_stack_user */
+#define PERF_ATTR_SIZE_VER4	104	/* add: sample_regs_intr */
 /*
  * Hardware event_id to monitor via a performance monitoring event:
 	/* Align to u64. */
 	__u32	__reserved_2;
+	/*
+	 * Defines set of regs to dump for each sample
+	 * state captured on:
+	 *  - precise = 0: PMU interrupt
+	 *  - precise > 0: sampled instruction
+	 *
+	 * See asm/perf_regs.h for details.
+	 */
+	__u64	sample_regs_intr;
 };
 #define perf_flags(attr)	(*(&(attr)->read_format + 1))
 	 *	{ u64			weight;   } && PERF_SAMPLE_WEIGHT
 	 *	{ u64			data_src; } && PERF_SAMPLE_DATA_SRC
 	 *	{ u64			transaction; } && PERF_SAMPLE_TRANSACTION
+	 *	{ u64			abi; # enum perf_sample_regs_abi
+	 *	  u64			regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR
 	 * };
 	 */
 	PERF_RECORD_SAMPLE			= 9,