diff options
Diffstat (limited to 'arch/x86/events/intel/lbr.c')
| -rw-r--r-- | arch/x86/events/intel/lbr.c | 77 |
1 files changed, 44 insertions, 33 deletions
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 78cd5084104e..f44c3d866f24 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -2,6 +2,7 @@ #include <linux/perf_event.h> #include <linux/types.h> +#include <asm/cpu_device_id.h> #include <asm/perf_event.h> #include <asm/msr.h> @@ -421,11 +422,17 @@ static __always_inline bool lbr_is_reset_in_cstate(void *ctx) return !rdlbr_from(((struct x86_perf_task_context *)ctx)->tos, NULL); } +static inline bool has_lbr_callstack_users(void *ctx) +{ + return task_context_opt(ctx)->lbr_callstack_users || + x86_pmu.lbr_callstack_users; +} + static void __intel_pmu_lbr_restore(void *ctx) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - if (task_context_opt(ctx)->lbr_callstack_users == 0 || + if (!has_lbr_callstack_users(ctx) || task_context_opt(ctx)->lbr_stack_state == LBR_NONE) { intel_pmu_lbr_reset(); return; @@ -502,7 +509,7 @@ static void __intel_pmu_lbr_save(void *ctx) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); - if (task_context_opt(ctx)->lbr_callstack_users == 0) { + if (!has_lbr_callstack_users(ctx)) { task_context_opt(ctx)->lbr_stack_state = LBR_NONE; return; } @@ -515,32 +522,11 @@ static void __intel_pmu_lbr_save(void *ctx) cpuc->last_log_id = ++task_context_opt(ctx)->log_id; } -void intel_pmu_lbr_swap_task_ctx(struct perf_event_pmu_context *prev_epc, - struct perf_event_pmu_context *next_epc) -{ - void *prev_ctx_data, *next_ctx_data; - - swap(prev_epc->task_ctx_data, next_epc->task_ctx_data); - - /* - * Architecture specific synchronization makes sense in case - * both prev_epc->task_ctx_data and next_epc->task_ctx_data - * pointers are allocated. - */ - - prev_ctx_data = next_epc->task_ctx_data; - next_ctx_data = prev_epc->task_ctx_data; - - if (!prev_ctx_data || !next_ctx_data) - return; - - swap(task_context_opt(prev_ctx_data)->lbr_callstack_users, - task_context_opt(next_ctx_data)->lbr_callstack_users); -} - -void intel_pmu_lbr_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in) +void intel_pmu_lbr_sched_task(struct perf_event_pmu_context *pmu_ctx, + struct task_struct *task, bool sched_in) { struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + struct perf_ctx_data *ctx_data; void *task_ctx; if (!cpuc->lbr_users) @@ -551,14 +537,18 @@ void intel_pmu_lbr_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched * the task was scheduled out, restore the stack. Otherwise flush * the LBR stack. */ - task_ctx = pmu_ctx ? pmu_ctx->task_ctx_data : NULL; + rcu_read_lock(); + ctx_data = rcu_dereference(task->perf_ctx_data); + task_ctx = ctx_data ? ctx_data->data : NULL; if (task_ctx) { if (sched_in) __intel_pmu_lbr_restore(task_ctx); else __intel_pmu_lbr_save(task_ctx); + rcu_read_unlock(); return; } + rcu_read_unlock(); /* * Since a context switch can flip the address space and LBR entries @@ -587,9 +577,19 @@ void intel_pmu_lbr_add(struct perf_event *event) cpuc->br_sel = event->hw.branch_reg.reg; - if (branch_user_callstack(cpuc->br_sel) && event->pmu_ctx->task_ctx_data) - task_context_opt(event->pmu_ctx->task_ctx_data)->lbr_callstack_users++; + if (branch_user_callstack(cpuc->br_sel)) { + if (event->attach_state & PERF_ATTACH_TASK) { + struct task_struct *task = event->hw.target; + struct perf_ctx_data *ctx_data; + rcu_read_lock(); + ctx_data = rcu_dereference(task->perf_ctx_data); + if (ctx_data) + task_context_opt(ctx_data->data)->lbr_callstack_users++; + rcu_read_unlock(); + } else + x86_pmu.lbr_callstack_users++; + } /* * Request pmu::sched_task() callback, which will fire inside the * regular perf event scheduling, so that call will: @@ -663,9 +663,19 @@ void intel_pmu_lbr_del(struct perf_event *event) if (!x86_pmu.lbr_nr) return; - if (branch_user_callstack(cpuc->br_sel) && - event->pmu_ctx->task_ctx_data) - task_context_opt(event->pmu_ctx->task_ctx_data)->lbr_callstack_users--; + if (branch_user_callstack(cpuc->br_sel)) { + if (event->attach_state & PERF_ATTACH_TASK) { + struct task_struct *task = event->hw.target; + struct perf_ctx_data *ctx_data; + + rcu_read_lock(); + ctx_data = rcu_dereference(task->perf_ctx_data); + if (ctx_data) + task_context_opt(ctx_data->data)->lbr_callstack_users--; + rcu_read_unlock(); + } else + x86_pmu.lbr_callstack_users--; + } if (event->hw.flags & PERF_X86_EVENT_LBR_SELECT) cpuc->lbr_select = 0; @@ -1457,7 +1467,7 @@ void __init intel_pmu_lbr_init_atom(void) * to have an operational LBR which can freeze * on PMU interrupt */ - if (boot_cpu_data.x86_model == 28 + if (boot_cpu_data.x86_vfm == INTEL_ATOM_BONNELL && boot_cpu_data.x86_stepping < 10) { pr_cont("LBR disabled due to erratum"); return; @@ -1693,6 +1703,7 @@ void x86_perf_get_lbr(struct x86_pmu_lbr *lbr) lbr->from = x86_pmu.lbr_from; lbr->to = x86_pmu.lbr_to; lbr->info = x86_pmu.lbr_info; + lbr->has_callstack = x86_pmu_has_lbr_callstack(); } EXPORT_SYMBOL_GPL(x86_perf_get_lbr); |