diff options
author | Borislav Petkov <borislav.petkov@amd.com> | 2011-10-16 17:15:04 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2011-11-14 13:31:26 +0100 |
commit | 9251f904f95175b4a1d8cbc0449e748f9edd7629 (patch) | |
tree | 585b73028c0c6b955d1759faf8544870eae213f5 /kernel/events/core.c | |
parent | Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git... (diff) | |
download | linux-9251f904f95175b4a1d8cbc0449e748f9edd7629.tar.xz linux-9251f904f95175b4a1d8cbc0449e748f9edd7629.zip |
perf: Carve out callchain functionality
Split the callchain code from the perf events core into
a new kernel/events/callchain.c file.
This simplifies a bit the big core.c
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
[keep ctx recursion handling inline and use internal headers]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1318778104-17152-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r-- | kernel/events/core.c | 209 |
1 files changed, 0 insertions, 209 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 0e8457da6f95..eadac69265fc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2570,215 +2570,6 @@ static u64 perf_event_read(struct perf_event *event) } /* - * Callchain support - */ - -struct callchain_cpus_entries { - struct rcu_head rcu_head; - struct perf_callchain_entry *cpu_entries[0]; -}; - -static DEFINE_PER_CPU(int, callchain_recursion[PERF_NR_CONTEXTS]); -static atomic_t nr_callchain_events; -static DEFINE_MUTEX(callchain_mutex); -struct callchain_cpus_entries *callchain_cpus_entries; - - -__weak void perf_callchain_kernel(struct perf_callchain_entry *entry, - struct pt_regs *regs) -{ -} - -__weak void perf_callchain_user(struct perf_callchain_entry *entry, - struct pt_regs *regs) -{ -} - -static void release_callchain_buffers_rcu(struct rcu_head *head) -{ - struct callchain_cpus_entries *entries; - int cpu; - - entries = container_of(head, struct callchain_cpus_entries, rcu_head); - - for_each_possible_cpu(cpu) - kfree(entries->cpu_entries[cpu]); - - kfree(entries); -} - -static void release_callchain_buffers(void) -{ - struct callchain_cpus_entries *entries; - - entries = callchain_cpus_entries; - rcu_assign_pointer(callchain_cpus_entries, NULL); - call_rcu(&entries->rcu_head, release_callchain_buffers_rcu); -} - -static int alloc_callchain_buffers(void) -{ - int cpu; - int size; - struct callchain_cpus_entries *entries; - - /* - * We can't use the percpu allocation API for data that can be - * accessed from NMI. Use a temporary manual per cpu allocation - * until that gets sorted out. - */ - size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]); - - entries = kzalloc(size, GFP_KERNEL); - if (!entries) - return -ENOMEM; - - size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS; - - for_each_possible_cpu(cpu) { - entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL, - cpu_to_node(cpu)); - if (!entries->cpu_entries[cpu]) - goto fail; - } - - rcu_assign_pointer(callchain_cpus_entries, entries); - - return 0; - -fail: - for_each_possible_cpu(cpu) - kfree(entries->cpu_entries[cpu]); - kfree(entries); - - return -ENOMEM; -} - -static int get_callchain_buffers(void) -{ - int err = 0; - int count; - - mutex_lock(&callchain_mutex); - - count = atomic_inc_return(&nr_callchain_events); - if (WARN_ON_ONCE(count < 1)) { - err = -EINVAL; - goto exit; - } - - if (count > 1) { - /* If the allocation failed, give up */ - if (!callchain_cpus_entries) - err = -ENOMEM; - goto exit; - } - - err = alloc_callchain_buffers(); - if (err) - release_callchain_buffers(); -exit: - mutex_unlock(&callchain_mutex); - - return err; -} - -static void put_callchain_buffers(void) -{ - if (atomic_dec_and_mutex_lock(&nr_callchain_events, &callchain_mutex)) { - release_callchain_buffers(); - mutex_unlock(&callchain_mutex); - } -} - -static int get_recursion_context(int *recursion) -{ - int rctx; - - if (in_nmi()) - rctx = 3; - else if (in_irq()) - rctx = 2; - else if (in_softirq()) - rctx = 1; - else - rctx = 0; - - if (recursion[rctx]) - return -1; - - recursion[rctx]++; - barrier(); - - return rctx; -} - -static inline void put_recursion_context(int *recursion, int rctx) -{ - barrier(); - recursion[rctx]--; -} - -static struct perf_callchain_entry *get_callchain_entry(int *rctx) -{ - int cpu; - struct callchain_cpus_entries *entries; - - *rctx = get_recursion_context(__get_cpu_var(callchain_recursion)); - if (*rctx == -1) - return NULL; - - entries = rcu_dereference(callchain_cpus_entries); - if (!entries) - return NULL; - - cpu = smp_processor_id(); - - return &entries->cpu_entries[cpu][*rctx]; -} - -static void -put_callchain_entry(int rctx) -{ - put_recursion_context(__get_cpu_var(callchain_recursion), rctx); -} - -static struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) -{ - int rctx; - struct perf_callchain_entry *entry; - - - entry = get_callchain_entry(&rctx); - if (rctx == -1) - return NULL; - - if (!entry) - goto exit_put; - - entry->nr = 0; - - if (!user_mode(regs)) { - perf_callchain_store(entry, PERF_CONTEXT_KERNEL); - perf_callchain_kernel(entry, regs); - if (current->mm) - regs = task_pt_regs(current); - else - regs = NULL; - } - - if (regs) { - perf_callchain_store(entry, PERF_CONTEXT_USER); - perf_callchain_user(entry, regs); - } - -exit_put: - put_callchain_entry(rctx); - - return entry; -} - -/* * Initialize the perf_event context in a task_struct: */ static void __perf_event_init_context(struct perf_event_context *ctx) |