hw_breakpoint creation needs to account stuff per-task to ensure there is always sufficient hardware resources to back these things due to ptrace. With the perf per pmu context changes the event initialization no longer has access to the event context, for the simple reason that we need to first find the pmu (result of initialization) before we can find the context. This makes hw_breakpoints unhappy, because it can no longer do per task accounting, cure this by frobbing a task pointer in the event::hw bits for now...
Showing the changes to include (1 of 3 files). Show all
Unified · Split
| @@ -536,6 +536,12 @@ struct hw_perf_event { · 535 unmodified lines | |||
| 536 | struct { /* breakpoint */ | 536 | struct { /* breakpoint */ |
| 537 | struct arch_hw_breakpoint info; | 537 | struct arch_hw_breakpoint info; |
| 538 | struct list_head bp_list; | 538 | struct list_head bp_list; |
| 539 | /* | ||
| 540 | * Crufty hack to avoid the chicken and egg | ||
| 541 | * problem hw_breakpoint has with context | ||
| 542 | * creation and event initalization. | ||
| 543 | */ | ||
| 544 | struct task_struct *bp_target; | ||
| 539 | }; | 545 | }; |
| 540 | #endif | 546 | #endif |
| 541 | }; | 547 | }; |
| @@ -693,6 +699,7 @@ struct swevent_hlist { · 151 unmodified lines | |||
| 693 | 699 | ||
| 694 | #define PERF_ATTACH_CONTEXT 0x01 | 700 | #define PERF_ATTACH_CONTEXT 0x01 |
| 695 | #define PERF_ATTACH_GROUP 0x02 | 701 | #define PERF_ATTACH_GROUP 0x02 |
| 702 | #define PERF_ATTACH_TASK 0x04 | ||
| 696 | 703 | ||
| 697 | /** | 704 | /** |
| 698 | * struct perf_event - performance event kernel representation: | 705 | * struct perf_event - performance event kernel representation: |