On Thu, Aug 23, 2018 at 07:42:09PM +0300, Alexey Budankov wrote:
>
> The data buffer and accompanying AIO control block are allocated at
> perf_mmap object and the mapped data buffer size is equal to
> the kernel one.
>
> The buffer is then used to preserve profiling data ready for dumping
> and queue it for asynchronous writing into perf trace thru implemented
> record__aio_write() function.
>
> mmap_aio control structure of the size equal to the number of per-cpu
> kernel buffers is used to keep pointers to enqueued AIO control
> blocks for monitoring of completed AIO operations.
>
> Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
> ---
> Changes in v2:
> - converted zalloc() to calloc() for allocation of mmap_aio array,
> - cleared typo and adjusted fallback branch code;
> ---
> tools/perf/builtin-record.c | 18 ++++++++++++++++++
> tools/perf/util/evlist.c | 7 +++++++
> tools/perf/util/evlist.h | 2 ++
> tools/perf/util/mmap.c | 12 ++++++++++++
> tools/perf/util/mmap.h | 3 +++
> 5 files changed, 42 insertions(+)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 22ebeb92ac51..a35675e9f3aa 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -53,6 +53,7 @@
> #include <sys/mman.h>
> #include <sys/wait.h>
> #include <linux/time64.h>
> +#include <aio.h>
>
> struct switch_output {
> bool enabled;
> @@ -121,6 +122,23 @@ static int record__write(struct record *rec, void *bf,
> size_t size)
> return 0;
> }
>
> +static int record__aio_write(int trace_fd, struct aiocb *cblock,
> + void *buf, size_t size, off_t off)
> +{
this breaks bisection:
builtin-record.c:125:12: error: ‘record__aio_write’ defined but not used
[-Werror=unused-function]
static int record__aio_write(int trace_fd, struct aiocb *cblock,
jirka
