To the very best of my knowledge there has never been any in-tree code that calls this function. It exists largely to support an out-of-tree driver that provides kgdb-over-ethernet using the netpoll API. kgdboe has been out-of-tree for more than 10 years and I don't recall any serious attempt to upstream it at any point in the last five. At this stage it looks better to stop carrying this code in the kernel and integrate the code into the out-of-tree driver instead. The long term trajectory for the kernel looks likely to include effort to remove or reduce the use of tasklets (something that has also been true for the last 10 years). Thus the main real reason for this patch is to make explicit that the in-tree kgdb features do not require tasklets.
Showing the changes to kernel/debug/debug_core.c (1 of 2 files). Show all
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| @@ -119,7 +119,6 @@ static DEFINE_RAW_SPINLOCK(dbg_slave_lock); · 118 unmodified lines | |||
| 119 | */ | 119 | */ |
| 120 | static atomic_t masters_in_kgdb; | 120 | static atomic_t masters_in_kgdb; |
| 121 | static atomic_t slaves_in_kgdb; | 121 | static atomic_t slaves_in_kgdb; |
| 122 | static atomic_t kgdb_break_tasklet_var; | ||
| 123 | atomic_t kgdb_setting_breakpoint; | 122 | atomic_t kgdb_setting_breakpoint; |
| 124 | 123 | ||
| 125 | struct task_struct *kgdb_usethread; | 124 | struct task_struct *kgdb_usethread; |
| @@ -1084,31 +1083,6 @@ static void kgdb_unregister_callbacks(void) · 958 unmodified lines | |||
| 1084 | } | 1083 | } |
| 1085 | } | 1084 | } |
| 1086 | 1085 | ||
| 1087 | /* | ||
| 1088 | * There are times a tasklet needs to be used vs a compiled in | ||
| 1089 | * break point so as to cause an exception outside a kgdb I/O module, | ||
| 1090 | * such as is the case with kgdboe, where calling a breakpoint in the | ||
| 1091 | * I/O driver itself would be fatal. | ||
| 1092 | */ | ||
| 1093 | static void kgdb_tasklet_bpt(unsigned long ing) | ||
| 1094 | { | ||
| 1095 | kgdb_breakpoint(); | ||
| 1096 | atomic_set(&kgdb_break_tasklet_var, 0); | ||
| 1097 | } | ||
| 1098 | |||
| 1099 | static DECLARE_TASKLET_OLD(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt); | ||
| 1100 | |||
| 1101 | void kgdb_schedule_breakpoint(void) | ||
| 1102 | { | ||
| 1103 | if (atomic_read(&kgdb_break_tasklet_var) || | ||
| 1104 | atomic_read(&kgdb_active) != -1 || | ||
| 1105 | atomic_read(&kgdb_setting_breakpoint)) | ||
| 1106 | return; | ||
| 1107 | atomic_inc(&kgdb_break_tasklet_var); | ||
| 1108 | tasklet_schedule(&kgdb_tasklet_breakpoint); | ||
| 1109 | } | ||
| 1110 | EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint); | ||
| 1111 | |||
| 1112 | /** | 1086 | /** |
| 1113 | * kgdb_register_io_module - register KGDB IO module | 1087 | * kgdb_register_io_module - register KGDB IO module |
| 1114 | * @new_dbg_io_ops: the io ops vector | 1088 | * @new_dbg_io_ops: the io ops vector |