Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 1 | /** |
Jon Medhurst | b1d0744 | 2015-05-08 12:04:18 +0100 | [diff] [blame] | 2 | * Copyright (C) ARM Limited 2010-2015. All rights reserved. |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include "gator.h" |
| 11 | #include <trace/events/sched.h> |
| 12 | |
| 13 | #define SCHED_SWITCH 0 |
| 14 | #define SCHED_TOTAL (SCHED_SWITCH+1) |
| 15 | |
| 16 | static ulong sched_switch_enabled; |
| 17 | static ulong sched_switch_key; |
| 18 | static DEFINE_PER_CPU(int[SCHED_TOTAL], schedCnt); |
| 19 | static DEFINE_PER_CPU(int[SCHED_TOTAL * 2], schedGet); |
| 20 | |
| 21 | #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 35) |
| 22 | GATOR_DEFINE_PROBE(sched_switch, TP_PROTO(struct rq *rq, struct task_struct *prev, struct task_struct *next)) |
| 23 | #else |
| 24 | GATOR_DEFINE_PROBE(sched_switch, TP_PROTO(struct task_struct *prev, struct task_struct *next)) |
| 25 | #endif |
| 26 | { |
| 27 | unsigned long flags; |
| 28 | |
Jon Medhurst | 96b5615 | 2014-10-30 18:01:15 +0000 | [diff] [blame] | 29 | /* disable interrupts to synchronize with gator_events_sched_read() |
| 30 | * spinlocks not needed since percpu buffers are used |
| 31 | */ |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 32 | local_irq_save(flags); |
| 33 | per_cpu(schedCnt, get_physical_cpu())[SCHED_SWITCH]++; |
| 34 | local_irq_restore(flags); |
| 35 | } |
| 36 | |
| 37 | static int gator_events_sched_create_files(struct super_block *sb, struct dentry *root) |
| 38 | { |
| 39 | struct dentry *dir; |
| 40 | |
| 41 | /* switch */ |
| 42 | dir = gatorfs_mkdir(sb, root, "Linux_sched_switch"); |
Jon Medhurst | 96b5615 | 2014-10-30 18:01:15 +0000 | [diff] [blame] | 43 | if (!dir) |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 44 | return -1; |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 45 | gatorfs_create_ulong(sb, dir, "enabled", &sched_switch_enabled); |
| 46 | gatorfs_create_ro_ulong(sb, dir, "key", &sched_switch_key); |
| 47 | |
| 48 | return 0; |
| 49 | } |
| 50 | |
| 51 | static int gator_events_sched_start(void) |
| 52 | { |
Jon Medhurst | 96b5615 | 2014-10-30 18:01:15 +0000 | [diff] [blame] | 53 | /* register tracepoints */ |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 54 | if (sched_switch_enabled) |
| 55 | if (GATOR_REGISTER_TRACE(sched_switch)) |
| 56 | goto sched_switch_exit; |
| 57 | pr_debug("gator: registered scheduler event tracepoints\n"); |
| 58 | |
| 59 | return 0; |
| 60 | |
Jon Medhurst | 96b5615 | 2014-10-30 18:01:15 +0000 | [diff] [blame] | 61 | /* unregister tracepoints on error */ |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 62 | sched_switch_exit: |
| 63 | pr_err("gator: scheduler event tracepoints failed to activate, please verify that tracepoints are enabled in the linux kernel\n"); |
| 64 | |
| 65 | return -1; |
| 66 | } |
| 67 | |
| 68 | static void gator_events_sched_stop(void) |
| 69 | { |
| 70 | if (sched_switch_enabled) |
| 71 | GATOR_UNREGISTER_TRACE(sched_switch); |
| 72 | pr_debug("gator: unregistered scheduler event tracepoints\n"); |
| 73 | |
| 74 | sched_switch_enabled = 0; |
| 75 | } |
| 76 | |
Jon Medhurst | 96b5615 | 2014-10-30 18:01:15 +0000 | [diff] [blame] | 77 | static int gator_events_sched_read(int **buffer, bool sched_switch) |
Jon Medhurst | aaf37a3 | 2013-06-11 12:10:56 +0100 | [diff] [blame] | 78 | { |
| 79 | unsigned long flags; |
| 80 | int len, value; |
| 81 | int cpu = get_physical_cpu(); |
| 82 | |
| 83 | len = 0; |
| 84 | if (sched_switch_enabled) { |
| 85 | local_irq_save(flags); |
| 86 | value = per_cpu(schedCnt, cpu)[SCHED_SWITCH]; |
| 87 | per_cpu(schedCnt, cpu)[SCHED_SWITCH] = 0; |
| 88 | local_irq_restore(flags); |
| 89 | per_cpu(schedGet, cpu)[len++] = sched_switch_key; |
| 90 | per_cpu(schedGet, cpu)[len++] = value; |
| 91 | } |
| 92 | |
| 93 | if (buffer) |
| 94 | *buffer = per_cpu(schedGet, cpu); |
| 95 | |
| 96 | return len; |
| 97 | } |
| 98 | |
| 99 | static struct gator_interface gator_events_sched_interface = { |
| 100 | .create_files = gator_events_sched_create_files, |
| 101 | .start = gator_events_sched_start, |
| 102 | .stop = gator_events_sched_stop, |
| 103 | .read = gator_events_sched_read, |
| 104 | }; |
| 105 | |
| 106 | int gator_events_sched_init(void) |
| 107 | { |
| 108 | sched_switch_enabled = 0; |
| 109 | |
| 110 | sched_switch_key = gator_events_get_key(); |
| 111 | |
| 112 | return gator_events_install(&gator_events_sched_interface); |
| 113 | } |