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| author |   Frederic Weisbecker <fweisbec@gmail.com> | 2010-08-14 20:45:13 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2010-08-19 01:32:53 +0200 |
| commit | 7ae07ea3a48d30689ee037cb136bc21f0b37d8ae (patch) | |
| tree | 2cb895a0794bcb2e45a4f48ef7e93302c1f6332c | |
| parent | perf: Fix race in callchains (diff) | |
| download | linux-dev-7ae07ea3a48d30689ee037cb136bc21f0b37d8ae.tar.xz linux-dev-7ae07ea3a48d30689ee037cb136bc21f0b37d8ae.zip | |
perf: Humanize the number of contexts
Instead of hardcoding the number of contexts for the recursions
barriers, define a cpp constant to make the code more
self-explanatory.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
| -rw-r--r-- | include/linux/perf_event.h | 14 | ||||
| -rw-r--r-- | kernel/perf_event.c | 4 | ||||
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 8 |
3 files changed, 14 insertions, 12 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index d7e8ea690864..ae6fa6050925 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -808,6 +808,12 @@ struct perf_event_context { struct rcu_head rcu_head; }; +/* + * Number of contexts where an event can trigger: + * task, softirq, hardirq, nmi. + */ +#define PERF_NR_CONTEXTS 4 + /** * struct perf_event_cpu_context - per cpu event context structure */ @@ -821,12 +827,8 @@ struct perf_cpu_context { struct mutex hlist_mutex; int hlist_refcount; - /* - * Recursion avoidance: - * - * task, softirq, irq, nmi context - */ - int recursion[4]; + /* Recursion avoidance in each contexts */ + int recursion[PERF_NR_CONTEXTS]; }; struct perf_output_handle { diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 75ab8a2df6b2..f416aef242c3 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1772,7 +1772,7 @@ struct callchain_cpus_entries { struct perf_callchain_entry *cpu_entries[0]; }; -static DEFINE_PER_CPU(int, callchain_recursion[4]); +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; @@ -1828,7 +1828,7 @@ static int alloc_callchain_buffers(void) if (!entries) return -ENOMEM; - size = sizeof(struct perf_callchain_entry) * 4; + size = sizeof(struct perf_callchain_entry) * PERF_NR_CONTEXTS; for_each_possible_cpu(cpu) { entries->cpu_entries[cpu] = kmalloc_node(size, GFP_KERNEL, diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 000e6e85b445..db2eae2efcf2 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -9,7 +9,7 @@ #include <linux/kprobes.h> #include "trace.h" -static char *perf_trace_buf[4]; +static char *perf_trace_buf[PERF_NR_CONTEXTS]; /* * Force it to be aligned to unsigned long to avoid misaligned accesses @@ -45,7 +45,7 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event, char *buf; int i; - for (i = 0; i < 4; i++) { + for (i = 0; i < PERF_NR_CONTEXTS; i++) { buf = (char *)alloc_percpu(perf_trace_t); if (!buf) goto fail; @@ -65,7 +65,7 @@ fail: if (!total_ref_count) { int i; - for (i = 0; i < 4; i++) { + for (i = 0; i < PERF_NR_CONTEXTS; i++) { free_percpu(perf_trace_buf[i]); perf_trace_buf[i] = NULL; } @@ -140,7 +140,7 @@ void perf_trace_destroy(struct perf_event *p_event) tp_event->perf_events = NULL; if (!--total_ref_count) { - for (i = 0; i < 4; i++) { + for (i = 0; i < PERF_NR_CONTEXTS; i++) { free_percpu(perf_trace_buf[i]); perf_trace_buf[i] = NULL; } |