diff options
author | Robert Richter <robert.richter@amd.com> | 2008-12-25 17:26:07 +0100 |
---|---|---|
committer | Robert Richter <robert.richter@amd.com> | 2009-01-07 22:37:44 +0100 |
commit | 2cc28b9f261dd28d69767a34682ce55a27d928ed (patch) | |
tree | eb99ee33781cc79ab09f2d70c93f14c90c664f91 /drivers/oprofile/cpu_buffer.c | |
parent | d358e75fc40cc3bbab11654ba0a88b232c543d12 (diff) |
oprofile: add op_cpu_buffer_write_reserve()
This function prepares the cpu buffer to write a sample.
Struct op_entry is used during operations on the ring buffer while
struct op_sample contains the data that is stored in the ring
buffer. Struct entry can be uninitialized. The function reserves a
data array that is specified by size. Use op_cpu_buffer_write_commit()
after preparing the sample. In case of errors a null pointer is
returned, otherwise the pointer to the sample.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Diffstat (limited to 'drivers/oprofile/cpu_buffer.c')
-rw-r--r-- | drivers/oprofile/cpu_buffer.c | 43 |
1 files changed, 30 insertions, 13 deletions
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index ac79f6676033..934ff159e70e 100644 --- a/drivers/oprofile/cpu_buffer.c +++ b/drivers/oprofile/cpu_buffer.c @@ -1,11 +1,12 @@ /** * @file cpu_buffer.c * - * @remark Copyright 2002 OProfile authors + * @remark Copyright 2002-2009 OProfile authors * @remark Read the file COPYING * * @author John Levon <levon@movementarian.org> * @author Barry Kasindorf <barry.kasindorf@amd.com> + * @author Robert Richter <robert.richter@amd.com> * * Each CPU has a local buffer that stores PC value/event * pairs. We also log context switches when we notice them. @@ -143,20 +144,36 @@ void end_cpu_work(void) flush_scheduled_work(); } -int op_cpu_buffer_write_entry(struct op_entry *entry) +/* + * This function prepares the cpu buffer to write a sample. + * + * Struct op_entry is used during operations on the ring buffer while + * struct op_sample contains the data that is stored in the ring + * buffer. Struct entry can be uninitialized. The function reserves a + * data array that is specified by size. Use + * op_cpu_buffer_write_commit() after preparing the sample. In case of + * errors a null pointer is returned, otherwise the pointer to the + * sample. + * + */ +struct op_sample +*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size) { - entry->event = ring_buffer_lock_reserve(op_ring_buffer_write, - sizeof(struct op_sample), - &entry->irq_flags); + entry->event = ring_buffer_lock_reserve + (op_ring_buffer_write, sizeof(struct op_sample) + + size * sizeof(entry->sample->data[0]), &entry->irq_flags); if (entry->event) entry->sample = ring_buffer_event_data(entry->event); else entry->sample = NULL; if (!entry->sample) - return -ENOMEM; + return NULL; - return 0; + entry->size = size; + entry->data = entry->sample->data; + + return entry->sample; } int op_cpu_buffer_write_commit(struct op_entry *entry) @@ -192,14 +209,14 @@ op_add_sample(struct oprofile_cpu_buffer *cpu_buf, unsigned long pc, unsigned long event) { struct op_entry entry; - int ret; + struct op_sample *sample; - ret = op_cpu_buffer_write_entry(&entry); - if (ret) - return ret; + sample = op_cpu_buffer_write_reserve(&entry, 0); + if (!sample) + return -ENOMEM; - entry.sample->eip = pc; - entry.sample->event = event; + sample->eip = pc; + sample->event = event; return op_cpu_buffer_write_commit(&entry); } |